Add PR checks

Author: mbarton

.github/workflows/check.yml

@@ -0,0 +1,22 @@
+name: Check build and tests on PR and merge to live
+
+on:
+  pull_request:
+    branches:
+      - "*"
+  push:
+    branches:
+      - live
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+          registry-url: "https://registry.npmjs.org"
+      - run: npm install
+      - run: npm run build
+      - run: npm test