Add GitHub Actions workflow for automated handbook generation

.github/workflows/regenerate-handbook.yml

@@ -0,0 +1,60 @@
+name: Regenerate Handbook
+
+on:
+  workflow_dispatch:
+  repository_dispatch:
+    types: [regenerate-handbook]
+
+permissions:
+  contents: write
+
+jobs:
+  regenerate:
+    name: Regenerate handbook
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out source code
+        uses: actions/checkout@v4
+
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 'latest'
+          coverage: none
+
+      - name: Install Composer dependencies
+        run: composer install --no-dev
+
+      - name: Download WP-CLI nightly
+        run: |
+          curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli-nightly.phar
+          chmod +x wp-cli-nightly.phar
+          sudo mv wp-cli-nightly.phar /usr/local/bin/wp
+
+      - name: Verify WP-CLI installation
+        run: wp --info
+
+      - name: Install non-bundled packages
+        run: |
+          chmod +x bin/install_packages.sh
+          bash bin/install_packages.sh
+
+      - name: Generate handbook
+        run: WP_CLI_PACKAGES_DIR=bin/packages WP_CLI_CONFIG_PATH=/dev/null wp handbook gen-all
+
+      - name: Check for changes
+        id: changes
+        run: |
+          git diff --exit-code --quiet HEAD || echo "has_changes=true" >> $GITHUB_OUTPUT
+
+      - name: Commit changes
+        if: steps.changes.outputs.has_changes == 'true'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git commit -m "Regenerate handbook"
+
+      - name: Push changes
+        if: steps.changes.outputs.has_changes == 'true'
+        run: git push

README.md

@@ -19,6 +19,21 @@ bin/install_packages.sh
 WP_CLI_PACKAGES_DIR=bin/packages WP_CLI_CONFIG_PATH=/dev/null wp handbook gen-all
 ```
 
+## Automated Handbook Generation
+
+The handbook can be regenerated automatically using the "Regenerate Handbook" GitHub Actions workflow. This workflow can be triggered in two ways:
+
+1. **Manual trigger**: Navigate to the Actions tab in the GitHub repository and run the "Regenerate Handbook" workflow manually.
+2. **Automated trigger from wp-cli/wp-cli**: When a new version of WP-CLI is released, the main framework repository can trigger this workflow using a `repository_dispatch` event with type `regenerate-handbook`.
+
+The workflow will:
+- Install WP-CLI nightly build
+- Install non-bundled packages
+- Run `wp handbook gen-all`
+- Commit and push any changes to the repository
+
+## Documentation Import
+
 All documentation is imported automatically into WordPress.org in a two step process:
 
 1. WordPress reads `commands-manifest.json` or `handbook-manifest.json` to understand all pages that need to be created.