Add post step to update search engines

[gkorland]

Post docs new publish google search and bing and perhaps other search engines should be notified.

E.g.

# Google Indexing
      - name: Notify Google
        uses: robingenz/google-indexing-action@main
        with:
          siteUrl: 'https://docs.falkordb.com'
          gcpServiceAccountKey: ${{ secrets.GCP_SERVICE_ACCOUNT_JSON }}

      # Bing + DuckDuckGo + Yandex via IndexNow
      - name: Notify Bing (IndexNow)
        uses: bojieyang/indexnow-action@v2
        with:
          sitemap-location: 'https://docs.falkordb.com/sitemap.xml'
          key: ${{ secrets.INDEXNOW_KEY }}

      # Generate IndexNow key file during build
      # (add this BEFORE your pages deploy step)
      # - name: Setup IndexNow key file
      #   run: echo "${{ secrets.INDEXNOW_KEY }}" > ./site/${{ secrets.INDEXNOW_KEY }}.txt