ci: add a ci.yaml for PRs and pushes to main (#30)

Author: sambarnes

.github/workflows/ci.yaml

@@ -0,0 +1,23 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+      - uses: pnpm/action-setup@v4
+      - run: pnpm install
+      - run: pnpm typecheck
+      - run: pnpm build
+      - run: pnpm test