ci(github): Add stylua check

.github/workflows/formatting.yaml

@@ -0,0 +1,16 @@
+name: stylua
+on:
+  push:
+    branches: ["main"]
+    paths-ignore:
+      - ".github/**"
+
+jobs:
+  stylua:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: JohnnyMorganz/stylua-action@1.0.0
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --check --config-path=.stylua.toml .