ci: add GitHub Actions workflow for deploying documentation

Author: hendriknielaender

.github/workflows/deploy-docs.yml

@@ -0,0 +1,39 @@
+name: Deploy Documentation
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mlugg/setup-zig@v1
+        with:
+          version: 0.14.0
+      - run: zig build docs
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./zig-out/docs
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+
+    permissions:
+      pages: write
+      id-token: write
+
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4
+