Update README.md

Author: davetcc

README.md

@@ -38,6 +38,8 @@ Community questions can be asked in the discussions section of this repo, or usi
 
 We're slowly transitioning to the designer being a web based tool. It can already generate nearly all existing menu, handle all existing plugins, and in addition supports a new fluent mode where the output is much cleaner.
 
+**Note at the moment for All-In-One or Fluent API mode you need to use the `main` repository version of TcMenu Library as 4.5.x is still undergoing testing before we release it.**
+
 * [Web based TcMenu Designer Turbo](https://designer.thecoderscorner.com)
 * [Documentation and starter page for Designer Turbo](https://www.thecoderscorner.com/products/apps/tcmenu-designer/)