[skip ci] update readme

Author: mostroverkhov

README.md

@@ -13,7 +13,7 @@ It enables following symmetric interaction models:
 *  channel (bi-directional streams)
 *  per-stream and per-RSocket metadata 
 
-##### RPC style interactions support is provided by [RSOCKET RPC - KOTLIN](https://github.com/rsocket/rsocket-rpc-kotlin) 
+#### RPC style interactions support is provided by [RSOCKET RPC - KOTLIN](https://github.com/rsocket/rsocket-rpc-kotlin) 
 
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