chore(ci): update example flake on push

.github/workflows/update-example.yaml

@@ -0,0 +1,24 @@
+name: Update example flake
+
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write
+
+jobs:
+  update-example:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v25
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+      - run: nix flake lock --update-input neovim-nix ./example
+      - run: |
+          git config --global user.name 'github-actions[bot]'
+          git config --global user.email 'willruggiano@users.noreply.github.com'
+          git commit -am 'chore: update example' || exit 0
+          git push