Update README.md

Author: XiaoPangxie732

README.md

@@ -1,5 +1,6 @@
 # MojangAPI-in-Java
 Mojang Public API Java implementation.  
+Usage is in the [wiki](https://github.com/XiaoPangxie732/MojangAPI-in-Java/wiki)  
 ## It is still in development.
 
 ## Download
@@ -24,4 +25,4 @@ Javadoc: [Click here](https://maxpixel.cn:20443/xiaopangxie732/projects/mojang-a
 1.Install Maven.  
 2.cd to source directory.  
 3.Run <code>mvn clean install</code>  
-4.When build complete, files are all in target folder. 
+4.When build complete, files are all in target folder.