fix readme

Author: Ashesh Vidyut

README.md

@@ -163,7 +163,7 @@ This graph shows the performance comparison between Treds - ScanKeys and Etcd ge
 * `PPUBLISH channel message` - This command publishes the message to all channels that have names with the given channel as their prefix.
 
 ### Note on channels
-* Usecase of channels designed with Prefix
+#### Use case of channels designed with Prefix
 
 While `PUBLISH` and `SUBSCRIBE` are similar to Redis, `PSUBSCRIBE` and `PPUBLISH` are designed to work with channels having a common prefix.