Fix markdown syntax in documentation

Although it is small mistake, it might make an affects while reading.

Signed-off-by: Nguyen Hai Truong <[email protected]>

Author: Nguyen Hai Truong

docs/user_guide/multi_machines_deployment.md

@@ -16,7 +16,7 @@ Then, we must provide:
 
     - **dfsupernode**: Dragonfly server
     - **dfclient0**: Dragonfly client one
-    - ****dfclient1**: Dragonfly client two
+    - **dfclient1**: Dragonfly client two
 
 2. every node has deployed docker daemon