readme with package description, usage details & see also block

Author: itnelo

README.md

@@ -1,7 +1,42 @@
 
 # ReactPHP WebDriver
 
-TBD
+This is a direct port of [RemoteWebDriver](https://github.com/php-webdriver/php-webdriver/blob/1.8.3/lib/Remote/RemoteWebDriver.php)
+logic from the [php-webdriver/webdriver](https://github.com/php-webdriver/php-webdriver) package, which utilizes [ReactPHP](https://github.com/reactphp/reactphp)
+event loop and promise API for browser interaction w/o execution flow blocking.
+
+Usage example:
+
+```php
+use React\EventLoop\Factory as LoopFactory;
+use React\Http\Browser;
+use Itnelo\React\WebDriver\Client\W3CClient;
+
+$loop = LoopFactory::create();
+$browser = new Browser($loop);
+    
+$webdriver = new W3CClient(
+    $browser,
+    [
+        'server' => [
+            'host' => 'selenium-hub',
+            'port' => 4444,
+        ],
+        'request' => [
+            'timeout' => 30,
+        ],
+    ]
+);
+```
+
+See a self-documented [ClientInterface.php](src/ClientInterface.php) for the API details. Not all methods are ported
+(only the most necessary), so feel free to open an issue / make a pull request if you want more.
+
+## See also
+
+- [php-webdriver/webdriver](https://github.com/php-webdriver/php-webdriver) — the original, "blocking" implementation; 
+to get information how to use some advanced methods, for example, [WebDriverKeys](https://github.com/php-webdriver/php-webdriver/blob/main/lib/WebDriverKeys.php#L10)
+helper describes Unicode strings for sending special inputs to page elements (e.g. `Ctrl`, `Alt`, etc.).
 
 ## Changelog