ci: add test and fmt PR workflow

.github/workflows/test.yml

@@ -0,0 +1,27 @@
+name: test
+
+on:
+  pull_request:
+    branches: ["main"]
+  workflow_dispatch:
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{matrix.os}}
+    steps:
+      - uses: actions/checkout@v3
+      - uses: goto-bus-stop/setup-zig@v2
+        with:
+          version: 0.12.0
+      - run: zig build test
+  check-fmt:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: goto-bus-stop/setup-zig@v2
+        with:
+          version: 0.12.0
+      - run: zig fmt --check .