Add test build to pull requests (#294)

This checks that the site will actually build, which can help catch some errors.

Author: frankieroberto

.github/workflows/test-build.yml

@@ -0,0 +1,19 @@
+name: Test build
+
+on: pull_request
+
+jobs:
+  test_build:
+    name: Test build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version-file: .nvmrc
+      - name: Install dependencies
+        run: npm ci
+      - name: Build with Eleventy
+        run: npm run-script build