docs: align ruby gem guides with current config behavior

src/content/docs/ruby-gem/how-to/advanced-features.mdx

@@ -35,12 +35,16 @@ html2rss is designed to be memory-efficient:
 For websites with many items:
 
 ```yaml
-# Use specific selectors to limit items
+channel:
+  url: "https://example.com/articles"
 selectors:
   items:
     selector: ".article:not(.advertisement)" # Exclude ads
   title:
     selector: "h2" # More specific than generic selectors
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 ## Error Recovery
@@ -59,6 +63,16 @@ Optimize requests with appropriate headers:
 headers:
   Accept: "text/html,application/xhtml+xml" # Avoid JSON if not needed
   Accept-Encoding: "gzip, deflate" # Enable compression
+channel:
+  url: "https://example.com/articles"
+selectors:
+  items:
+    selector: "article"
+  title:
+    selector: "h2"
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 ## Monitoring and Debugging
@@ -98,13 +112,20 @@ Invalid articles are automatically filtered out to prevent empty or broken feed
 You can add custom validation by using post-processors:
 
 ```yaml
+channel:
+  url: "https://example.com/articles"
 selectors:
+  items:
+    selector: "article"
   title:
     selector: "h2"
     post_process:
       - name: "gsub"
         pattern: "^\\s*$"
         replacement: "Untitled"
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 ## Best Practices

src/content/docs/ruby-gem/how-to/custom-http-requests.mdx

@@ -3,7 +3,7 @@ title: "Custom HTTP Requests"
 description: "Learn how to customize HTTP requests with custom headers, authentication, and API interactions for html2rss."
 ---
 
-Some websites require custom HTTP headers, authentication, or specific request configurations to access their content. html2rss makes it easy to customize your requests to handle these scenarios.
+Some websites require custom HTTP headers, authentication, or other request settings to access their content. `html2rss` lets you customize requests for those cases.
 
 ## When You Need Custom Headers
 
@@ -17,7 +17,7 @@ You might need custom HTTP requests when:
 
 ## Basic Configuration
 
-Add a `headers` section to your feed configuration:
+Add a `headers` section to your feed configuration. This example is a complete, valid config:
 
 ```yaml
 headers:
@@ -28,9 +28,11 @@ channel:
   url: https://api.example.com/posts
 selectors:
   items:
-    selector: ".post"
+    selector: "array > object"
   title:
-    selector: "h2"
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 ## Common Use Cases
@@ -43,6 +45,15 @@ Many APIs require authentication tokens:
 headers:
   Authorization: "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
   X-API-Key: "your-api-key-here"
+channel:
+  url: "https://api.example.com/posts"
+selectors:
+  items:
+    selector: "array > object"
+  title:
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 ### User Agent Spoofing
@@ -55,6 +66,16 @@ headers:
   Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
   Accept-Language: "en-US,en;q=0.5"
   Accept-Encoding: "gzip, deflate"
+channel:
+  url: "https://example.com/articles"
+selectors:
+  items:
+    selector: "article"
+  title:
+    selector: "h2"
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 ### Content Type Negotiation
@@ -63,9 +84,16 @@ Request specific content types:
 
 ```yaml
 headers:
-  Accept: "application/json"  # For JSON APIs
-  Accept: "text/html"         # For HTML content
-  Accept: "application/rss+xml"  # For RSS feeds
+  Accept: "application/json"
+channel:
+  url: "https://api.example.com/posts"
+selectors:
+  items:
+    selector: "array > object"
+  title:
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 ### Custom API Headers
@@ -77,6 +105,15 @@ headers:
   X-Requested-With: "XMLHttpRequest"
   X-Custom-Header: "your-value"
   Content-Type: "application/json"
+channel:
+  url: "https://api.example.com/posts"
+selectors:
+  items:
+    selector: "array > object"
+  title:
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 ## Dynamic Headers
@@ -85,12 +122,27 @@ You can use dynamic parameters in headers for runtime values:
 
 ```yaml
 headers:
-  Authorization: "Bearer {{api_token}}"
-  X-User-ID: "{{user_id}}"
+  Authorization: "Bearer %<api_token>s"
+  X-User-ID: "%<user_id>s"
+channel:
+  url: "https://api.example.com/users/%<user_id>s/posts"
+selectors:
+  items:
+    selector: "array > object"
+  title:
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 See our [Dynamic Parameters guide](/ruby-gem/how-to/dynamic-parameters) for more details.
 
+## Notes
+
+- Header examples that target third-party APIs are illustrative. Authentication requirements, header names, and response shapes can change independently of `html2rss`.
+- For JSON APIs, validate the response structure before assuming selectors like `array > object` or `html_url` will match.
+- If you document or share a config for reuse, prefer placeholder values and parameterized headers over embedding real tokens.
+
 ## Testing Your Headers
 
 Test your configuration to ensure headers work correctly:
@@ -130,6 +182,13 @@ headers:
   User-Agent: "html2rss/1.0"
 channel:
   url: https://api.github.com/repos/owner/repo/issues
+selectors:
+  items:
+    selector: "array > object"
+  title:
+    selector: "title"
+  url:
+    selector: "html_url"
 ```
 
 ### Reddit API
@@ -140,6 +199,13 @@ headers:
   Accept: "application/json"
 channel:
   url: https://www.reddit.com/r/programming.json
+selectors:
+  items:
+    selector: "data > children > object > data"
+  title:
+    selector: "title"
+  url:
+    selector: "url"
 ```
 
 ## Related Topics

src/content/docs/ruby-gem/how-to/dynamic-parameters.mdx

@@ -3,17 +3,25 @@ title: Dynamic Parameters
 description: "Learn how to use dynamic parameters in URLs and headers for creating reusable feed configurations. Pass runtime values to customize feeds."
 ---
 
-For websites with similar structures but varying content based on a parameter in the URL or headers, you can use dynamic parameters.
+Use dynamic parameters when websites share the same structure but vary by URL or header values.
 
 ## Solution
 
 You can add dynamic parameters to the `channel` and `headers` values. This is useful for creating feeds from structurally similar pages with different URLs.
 
 ```yaml
 channel:
-  url: "http://domainname.tld/whatever/%<id>s.html"
+  url: "https://domainname.tld/whatever/%<id>s.html"
 headers:
   X-Something: "%<foo>s"
+selectors:
+  items:
+    selector: "article"
+  title:
+    selector: "h2"
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 You can then pass the values for these parameters when you run `html2rss`:
@@ -30,6 +38,12 @@ html2rss feed the_feed_config.yml --params id:42 foo:bar
 - You provide the actual values for these parameters at runtime using the `--params` option.
 - This allows you to reuse the same feed configuration for multiple similar pages or APIs.
 
+## Notes
+
+- Dynamic substitution applies to `channel` and `headers`. Selector definitions are not parameterized by this feature.
+- If a config references `%<param>s` and you do not provide a value, feed generation fails unless the caller supplies a fallback.
+- For shared config repositories such as `html2rss-configs`, it is common to store default parameter values alongside the config so examples, validation, and tests have concrete inputs.
+
 ## Related Topics
 
 - **[Custom HTTP Requests](/ruby-gem/how-to/custom-http-requests/)** - Using dynamic parameters in headers

src/content/docs/ruby-gem/how-to/managing-feed-configs.mdx

@@ -21,12 +21,24 @@ feeds:
     channel:
       url: "https://example.com/blog"
     selectors:
-      # ...
+      items:
+        selector: ".post"
+      title:
+        selector: "h2"
+      url:
+        selector: "a"
+        extractor: "href"
   my-second-feed:
     channel:
       url: "https://example.com/news"
     selectors:
-      # ...
+      items:
+        selector: ".news-item"
+      title:
+        selector: "h2"
+      url:
+        selector: "a"
+        extractor: "href"
 ```
 
 ## Building Feeds from a YAML File

src/content/docs/ruby-gem/how-to/scraping-json.mdx

@@ -68,10 +68,12 @@ Html2rss.feed(
     Accept: 'application/json'
   },
   channel: {
-    url: 'http://domainname.tld/whatever.json'
+    url: 'https://domainname.tld/whatever.json'
   },
   selectors: {
-    title: { selector: 'foo' }
+    items: { selector: 'array > object' },
+    title: { selector: 'title' },
+    url: { selector: 'url' }
   }
 )
 ```
@@ -82,10 +84,12 @@ Html2rss.feed(
 headers:
   Accept: application/json
 channel:
-  url: "http://domainname.tld/whatever.json"
+  url: "https://domainname.tld/whatever.json"
 selectors:
   items:
     selector: "array > object"
   title:
-    selector: "foo"
+    selector: ".title"
+  url:
+    selector: "url"
 ```

src/content/docs/ruby-gem/reference/auto-source.mdx

@@ -36,6 +36,8 @@ You can customize `auto_source` to improve its accuracy.
 Enable or disable specific scrapers and adjust their settings:
 
 ```yaml
+channel:
+  url: https://example.com
 auto_source:
   scraper:
     schema:
@@ -55,6 +57,8 @@ auto_source:
 Remove unwanted items from the results:
 
 ```yaml
+channel:
+  url: https://example.com
 auto_source:
   cleanup:
     keep_different_domain: false # default: true

src/content/docs/ruby-gem/reference/channel.mdx

@@ -3,7 +3,9 @@ title: Channel
 description: "Learn about the channel configuration block for RSS feed metadata. Configure feed title, description, author, and other RSS channel properties."
 ---
 
-The `channel` configuration block defines the metadata for your RSS feed.
+The `channel` configuration block defines your feed metadata.
+
+This example is a complete feed config so you can see the `channel` block in context:
 
 ```yaml
 channel:
@@ -12,8 +14,16 @@ channel:
   description: "A feed of the latest news from Example.com"
   author: "jane.doe@example.com (Jane Doe)"
   ttl: 60
-  language: "en-us"
+  language: "en"
   time_zone: "Europe/Berlin"
+selectors:
+  items:
+    selector: "article"
+  title:
+    selector: "h2"
+  url:
+    selector: "a"
+    extractor: "href"
 ```
 
 ## Options
@@ -28,6 +38,12 @@ channel:
 | `language`    | Optional     | The language of the feed. Defaults to the `lang` attribute of the `<html>` tag.                                                          |
 | `time_zone`   | Optional     | The time zone for parsing dates. See the [list of tz database time zones](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones). |
 
+## Notes
+
+- `language` is runtime-validated. Use a valid language code such as `en`, not an arbitrary string.
+- `author` should follow the RSS-style `email (Name)` format when you set it explicitly.
+- `time_zone` must be a known TZ database identifier such as `UTC` or `Europe/Berlin`.
+
 ---
 
 For detailed documentation on the Ruby API, see the [official YARD documentation](https://www.rubydoc.info/gems/html2rss).