Update README.md

Update link to the documentation.

Author: Aessi

README.md

@@ -1,7 +1,7 @@
 xml-rpc api for the game modes scripts
 ======================================
 
-- [Quick intro](https://v4.live.maniaplanet.com/documentation/dedicated-server/references/xml-rpc-scripts)
+- [Quick intro](https://doc.maniaplanet.com/dedicated-server/references/xml-rpc-scripts)
 - [Callbacks reference](https://github.com/maniaplanet/script-xmlrpc/blob/master/XmlRpcListing.md#callbacks)
 - [Methods reference](https://github.com/maniaplanet/script-xmlrpc/blob/master/XmlRpcListing.md#methods)
 - [Changelog](https://github.com/maniaplanet/script-xmlrpc/releases)