Publish built PDF to GitHub Pages

.github/workflows/compile.yml

@@ -1,6 +1,15 @@
 name: CI
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - main
+
+  pull_request:
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
 
 jobs:
   build:
@@ -29,8 +38,30 @@ jobs:
       run: |
         eval $(opam env) && make -C archdoc
         cp archdoc/cheriot-architecture.pdf install
+        mkdir -p _site/
+        cp archdoc/cheriot-architecture.pdf _site/
     - name: Upload simulator artifact
       uses: actions/upload-artifact@v4
       with:
         name: cheriot_sim
         path: install/
+
+  deploy:
+    # Run only when landing, not as part of a PR
+    if: ${{ github.event_name == 'push' }}
+
+    # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+    permissions:
+      contents: read
+      pages: write
+      id-token: write
+
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: [ubuntu-20.04]
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v2