Add workflow to build & deploy API docs on release

.github/workflows/publish.yml

@@ -6,12 +6,15 @@ permissions:
 on:
   release:
     types: [published]
+  # To manually trigger a rebuild of the API docs if needed
+  workflow_dispatch:
 
 jobs:
   publish:
     name: Langium Publish
     runs-on: ubuntu-latest
     timeout-minutes: 20
+    if: ${{ github.event_name == 'release' }}
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -56,3 +59,31 @@ jobs:
         PACKAGE_VERSION=`npm pkg get version --workspaces=false | tr -d \"`
         vsce package
         ovsx publish langium-vscode-$PACKAGE_VERSION.vsix -p ${{ secrets.OVSX_TOKEN }}
+
+  docs:
+    name: Build and publish API docs
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write      # to deploy to Pages
+      id-token: write   # to verify the deployment originates from an appropriate source
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '18'
+      - name: Build API docs
+        run: |
+          npm ci
+          npm run docs -w langium
+      - name: Upload docs artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: pacakges/langium/docs
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4