chore: Add GitHub Actions build workflow

Author: asbjornu

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: yarn
+      - run: yarn install --frozen-lockfile
+      - run: yarn build
+      - uses: tj-actions/changed-files@v41
+        with:
+          fail_on_initial_diff_error: true