Add CI/CD workflow for building slides and deploying website

- Build LaTeX slides automatically on push
- Upload PDF as artifact for each build
- Deploy website with slides to GitHub Pages

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: katoue

.github/workflows/build-and-deploy.yml

@@ -0,0 +1,59 @@
+name: Build and Deploy
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build-slides:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup LaTeX
+        uses: xu-cheng/latex-action@v3
+        with:
+          working_directory: slides
+          root_file: week2_slides.tex
+
+      - name: Upload PDF artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: slides-pdf
+          path: slides/week2_slides.pdf
+
+  deploy:
+    runs-on: ubuntu-latest
+    needs: build-slides
+    if: github.ref == 'refs/heads/main'
+    permissions:
+      contents: read
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Download slides PDF
+        uses: actions/download-artifact@v4
+        with:
+          name: slides-pdf
+          path: docs/slides
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v4
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4