add yarn format to CI since that's whats being run in lint-staged

Author: kcpevey

.github/workflows/test-website.yml

@@ -33,5 +33,8 @@ jobs:
       - name: Lint 🔍
         run: yarn run lint
 
+      - name: Format 🥇
+        run: yarn run format
+
       - name: Build site 🔨
         run: yarn run build