Adjust readme

Author: bcb

README.md

@@ -40,7 +40,9 @@ response = dispatch('{"jsonrpc": "2.0", "method": "ping", "id": 1}')
 # => '{"jsonrpc": "2.0", "result": "pong", "id": 1}'
 ```
 
-👉 Full documentation is at [explodinglabs.com/jsonrpcserver](https://explodinglabs.com/jsonrpcserver/).
+## 📚 Documentation
+
+👉 Full documentation is at [explodinglabs.com/jsonrpcserver/](https://explodinglabs.com/jsonrpcserver/).
 
 👉 See the [Wiki](https://github.com/explodinglabs/jsonrpcserver/wiki) for community-editable usage examples in various frameworks, libraries, and transport protocols.