add depedencies installation step in build workflow

Author: cpea2506

.github/workflows/build.yaml

@@ -10,6 +10,16 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+      - name: Install Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version-file: .nvmrc
+      - name: Install dependencies
+        run: npm ci
+      - name: Build extension
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: npm run build:css
       - name: Xcode build
         uses: sersoft-gmbh/xcodebuild-action@v2
         with: