docs: Add GH Pages workflow (#27)

* Add GH Pages workflow

* Clean up

.github/workflows/gh-pages.yaml

@@ -0,0 +1,26 @@
+name: Deploy example to GH Pages
+on:
+  push:
+    branches:
+      - main
+permissions:
+  contents: write
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Flutter
+        uses: subosito/flutter-action@v2
+        with:
+          flutter-version: "3.19.0"
+
+      - name: Build
+        run: cd example && flutter build web
+
+      - name: Deploy 🚀
+        uses: JamesIves/github-pages-deploy-action@v4
+        with:
+          folder: example/build