added CI to enforce cargo fmt based formatting

.github/workflows/rust-fmt.yml

@@ -0,0 +1,22 @@
+name: CI
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  pull_request:
+    branches:
+      - main
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  fmt:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/[email protected]
+        with:
+          components: rustfmt
+      - run: cargo fmt --all --check