Add workflow to generate real demo GIF with VHS

Author: Rohan5commit

.github/workflows/generate-demo.yml

@@ -0,0 +1,32 @@
+name: Generate Demo GIF
+
+on:
+  workflow_dispatch:
+
+jobs:
+  demo:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install package
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e .
+
+      - name: Render VHS demo
+        uses: charmbracelet/vhs-action@v2
+        with:
+          path: .github/demo.tape
+
+      - name: Upload demo artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: demo-gif
+          path: demo.gif