add generate-query-help workflow

.github/workflows/generate-query-help-docs.yml

@@ -0,0 +1,53 @@
+name: Generate CodeQL documentation using Sphinx
+
+on:
+  push:
+    branches:
+     - main
+     - 'rc/**'
+     - 'lgtm.com'
+  pull_request:
+    paths:
+      - 'docs/language/query-help/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Clone github/codeql
+      uses: actions/checkout@v2
+      with:
+        path: codeql 
+    - name: Clone github/codeql-go
+      uses: actions/checkout@v2
+      with:
+        repository: 'github/codeql-go'
+        path: codeql-go
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+    - name: Download CodeQL CLI
+      uses: dsaltares/fetch-gh-release-asset@aa37ae5c44d3c9820bc12fe675e8670ecd93bd1c
+      with:
+        repo: "github/codeql-cli-binaries"
+        version: "latest"
+        file: "codeql-linux64.zip"
+        token: ${{ secrets.GITHUB_TOKEN }}
+    - name: Unzip CodeQL CLI
+      run: unzip -d codeql-cli codeql-linux64.zip
+    - name: Query help to markdown
+      run: |
+        PATH="$PATH:codeql-cli/codeql" python codeql/docs/language/query-help-markdown.py
+    - name: Run Sphinx for query help
+      uses: ammaraskar/sphinx-action@master
+      with:
+        docs-folder: "codeql/docs/language/query-help/"
+        pre-build-command: "python -m pip install --upgrade recommonmark"
+        build-command: "sphinx-build -b html . query-help-build"  
+    - name: Upload HTML artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: query-help-html
+        path: query-help
+