docs: add pages workflow README

Author: Jani Giannoudis

.github/workflows/pages.md

@@ -0,0 +1,49 @@
+# Workflow: Deploy DocFX to GitHub Pages
+
+Builds the scripting API reference with [DocFX](https://dotnet.github.io/docfx/) and deploys it to GitHub Pages.
+
+## Trigger
+
+| Event | Condition |
+|:--|:--|
+| `release: published` | Runs automatically on every published release |
+| `workflow_dispatch` | Manual trigger via GitHub Actions UI |
+
+## Steps
+
+| Step | Description |
+|:--|:--|
+| Checkout | Checks out the repository |
+| Setup .NET | Installs .NET 10 SDK |
+| Configure GitHub Packages | Adds the Payroll-Engine NuGet feed using `PAT_DISPATCH` |
+| Build | `dotnet build Client.Scripting/PayrollEngine.Client.Scripting.csproj -c Release` |
+| Install DocFX | Installs the latest DocFX global tool |
+| Build DocFX | Runs `docfx docfx/docfx.json` — generates HTML into `docfx/_site/` |
+| Upload Pages artifact | Uploads `docfx/_site/` as the GitHub Pages artifact |
+| Deploy to GitHub Pages | Deploys the artifact to the `github-pages` environment |
+
+## Output
+
+👉 https://payroll-engine.github.io/PayrollEngine.Client.Scripting/
+
+## Permissions
+
+| Permission | Reason |
+|:--|:--|
+| `contents: read` | Checkout |
+| `pages: write` | Deploy to GitHub Pages |
+| `id-token: write` | OIDC token for Pages deployment |
+
+## Secrets
+
+| Secret | Usage |
+|:--|:--|
+| `PAT_DISPATCH` | Read access to the Payroll-Engine GitHub Packages NuGet feed |
+
+## Configuration
+
+DocFX is configured in `docfx/docfx.json`. The metadata source is the compiled assembly:
+
+```
+Client.Scripting/bin/Release/net10.0/PayrollEngine.*.dll
+```