automatic build & deploy PDF

* remove binary PDF blob from repo
* action to build & upload on PR to main
* action to build & upload to pages on merge to main

.github/workflows/generate_pdf.yml

@@ -0,0 +1,45 @@
+name: Generate PDF
+
+on:
+  # allows manual triggering of the workflow
+  workflow_dispatch:
+  # run on changes to main
+  push:
+    branches:
+      - main
+  # run on PRs to main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    # grant GITHUB_TOKEN permissions for pages deployment
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build
+        # wraps a LaTeX build environment
+        uses: xu-cheng/latex-action@v4
+        with:
+          root_file: M17_spec.tex
+
+      - name: Upload
+        uses: actions/upload-artifact@v4
+        with:
+          name: Specification
+          path: M17_spec.pdf
+
+      - name: Deploy
+        # only deploy on pushes to main, not on PRs
+        if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+        uses: actions/deploy-pages@v4