add to toc

Author: rustagir

docs/quick-start.txt

@@ -26,6 +26,7 @@ Quick Start
    View Data </quick-start/view-data/>
    Write Data </quick-start/write-data/>
    Next Steps </quick-start/next-steps/>
+   Tutorial: Build a Back End </quick-start/backend-service-tutorial>
 
 Overview
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