Add Google Analytics (GA4) to build workflow

Author: zackkatz

.github/workflows/deploy.yml

@@ -57,6 +57,8 @@ jobs:
       - name: Build site
         run: npm run build
         env:
+          # Google Analytics (GA4)
+          GOOGLE_GTAG_ID: ${{ vars.GOOGLE_GTAG_ID }}
           # Algolia DocSearch configuration (optional)
           ALGOLIA_APP_ID: ${{ secrets.ALGOLIA_APP_ID }}
           ALGOLIA_API_KEY: ${{ secrets.ALGOLIA_API_KEY }}