Update index.md

Author: makasim

docs/index.md

@@ -42,7 +42,7 @@
 * Magento
     - [Quick tour](magento/quick_tour.md)
     - [Cli commands](magento/cli_commands.md)
-* [Use cases]
+* [Use cases](#use-cases)
     - [FOSElasticaBundle. Populate command optimizations](elastica-bundle/populate-command-optimization.md)
     - [Symfony. Async event dispatcher](async_event_dispatcher/quick_tour.md)
 * Development