github: add workflow to test the docusaurus build

Signed-off-by: Christian Berendt <[email protected]>

.github/workflows/build.yml

@@ -0,0 +1,20 @@
+name: Build
+
+on:
+  pull_request:
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+          cache: yarn
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+      - name: Build
+        run: yarn build