Add GitHub Actions workflow for Pages deployment

Triggers on pushes to main when JSON files, templates, or static
assets change. Runs generate.py to build HTML pages and snippets.json,
then deploys to GitHub Pages.

Requires Pages source set to 'GitHub Actions' in repo settings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: brunoborges

.github/workflows/deploy.yml

@@ -0,0 +1,58 @@
+name: Deploy to GitHub Pages
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - '*/**.json'
+      - 'slug-template.html'
+      - 'generate.py'
+      - 'index.html'
+      - 'styles.css'
+      - 'app.js'
+      - 'manifest.json'
+      - 'favicon.svg'
+      - 'assets/**'
+      - 'images/**'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Generate HTML pages and snippets.json
+        run: python3 generate.py
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: .
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4