Add a suite of Rust-related actions (#55)

* Add a suite of Rust-related actions

* cargo fmt

* nightly for rustdoc

.github/workflows/rust-tests.yml

@@ -0,0 +1,42 @@
+name: tests - rust
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+jobs:
+  test:
+    strategy:
+      # A simple matrix for now, but if we introduce an MSRV it can be added here.
+      matrix:
+        rust:
+          - "stable"
+
+    runs-on: ubuntu-latest
+    name: "rust ${{ matrix.rust }}"
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Cache cargo registry
+        uses: actions/cache@v4
+        with:
+          path: ~/.cargo/registry
+          key: ${{ runner.os }}-${{ matrix.rust }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Cache cargo build
+        uses: actions/cache@v4
+        with:
+          path: target
+          key: ${{ runner.os }}-${{ matrix.rust }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: "${{ matrix.rust }}"
+          override: true
+
+      - name: test
+        run: cargo test