refactor: move to github actions to build site

.github/workflows/build.yml

@@ -0,0 +1,55 @@
+name: Build Site
+
+on:
+  push:
+    branches: ['sources', 'generator']
+  pull_request:
+    branches: ['sources', 'generator']
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: sources
+          path: sources
+
+      - uses: actions/checkout@v4
+        with:
+          ref: generator
+          path: generator
+
+      - name: Copy files
+        run: |
+          cp -a generator/webroot workdir
+          cp -a sources/{post,content.php,index.md} generator/{mdgen.py,sitegen.php} workdir
+          mv workdir/img/favicon.ico workdir/favicon.ico
+
+      - name: Generate site
+        run: |
+          cd workdir
+          php sitegen.php
+          rm -r post/*.md index.md *.{py,php}
+
+      - name: Upload GitHub Pages artifact
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: workdir
+
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    permissions:
+      contents: read
+      pages: write
+      id-token: write
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4