Add GitHub workflow

.github/workflows/ci.yml

@@ -0,0 +1,47 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  check:
+    name: Lint & Format
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+          components: rustfmt, clippy
+
+      - name: Cargo fmt
+        run: cargo fmt --all -- --check
+
+      - name: Cargo clippy
+        run: cargo clippy --all-targets --all-features -- -D warnings
+
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: nextest
+
+      - name: Run tests
+        run: cargo nextest run --all-features --all-targets
+
+env:
+  CARGO_TERM_COLOR: always