style: fmt the project (#54)

add rustfmt.toml

Signed-off-by: jokemanfire <hu.dingyang@zte.com.cn>

.github/workflows/ci.yml

@@ -41,11 +41,11 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - name: Install Rust
-        uses: dtolnay/rust-toolchain@stable
+      - name: Install Rust fmt
+        run: rustup toolchain install nightly --component rustfmt
 
       - name: Check formatting
-        run: cargo fmt --all -- --check
+        run: cargo +nightly fmt --all -- --check
 
   clippy:
     name: Lint with Clippy