Adds Rust CI.

.github/workflows/ci.yaml

@@ -0,0 +1,25 @@
+name: "Rust CI"
+on:
+  pull_request:
+
+jobs:
+  build:
+    name: cargo build and test
+    # Needs big runner for the test.
+    runs-on: ubuntu-22.04-github-hosted-16core
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: cargo build --verbose
+      - run: cargo test --verbose --all
+
+  formatting:
+    name: cargo fmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          components: rustfmt
+      - name: Rustfmt Check
+        uses: actions-rust-lang/rustfmt@v1