🚧 add rustfmt to CI/CD

.github/workflows/rust.yml

@@ -46,3 +46,19 @@ jobs:
           -f .github/archlinux/Dockerfile \
           --load \
           .
+
+  fmt:
+    name: rust fmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: nightly
+          override: true
+          components: rustfmt
+      - uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check