Add reference to ui-example branch in readme

Author: Mr-Wiseguy

README.md

@@ -2,6 +2,8 @@
 
 This is an example mod for Majora's Mask: Recompiled that can be used as a template for creating mods. It has a basic build system, headers, sample code, and a mod config toml.
 
+Example code for using the recompui API to build ingame UI can be found in the `ui-example` branch.
+
 ### Writing mods
 See [this document](https://hackmd.io/fMDiGEJ9TBSjomuZZOgzNg) for an explanation of the modding framework, including how to write function patches and perform interop between different mods.