fix: fix clippy, update readme

Author: vivianjeng

.github/workflows/build-and-test.yml

@@ -19,6 +19,11 @@ jobs:
           toolchain: stable
           override: true
           components: rustfmt, clippy
+      - name: install requirements
+        uses: awalsh128/cache-apt-pkgs-action@v1
+        with:
+          packages: protobuf-compiler
+          version: 1.0
       - name: cargo fmt
         run: cargo fmt --all -- --check
       - name: cargo clippy