feat(tests) Add GHA workflow to run unit tests on PR + main

Ensure that we don't sneak in irregular template modifications

.github/workflows/tests.yaml

@@ -0,0 +1,23 @@
+name: Tests
+
+on:
+  pull_requests:
+  push:
+    branches:
+      - main
+
+jobs:
+  unit-tests:
+    name: Unit Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4.1.1
+      - name: Setup node.js
+        uses: actions/setup-node@v4.0.0
+        with:
+          node-version: 18
+      - name: Run unit tests
+        run: npm test
+
+