Branch point for 2021 May 29 Breaking Change

readme.md

@@ -9,6 +9,12 @@
 
 This is a keyboard firmware based on the [tmk\_keyboard firmware](https://github.com/tmk/tmk_keyboard) with some useful features for Atmel AVR and ARM controllers, and more specifically, the [OLKB product line](https://olkb.com), the [ErgoDox EZ](https://ergodox-ez.com) keyboard, and the [Clueboard product line](https://clueboard.co).
 
+# THIS IS THE DEVELOP BRANCH
+
+Warning- This is the `develop` branch of QMK Firmware. You may encounter broken code here. Please see [Breaking Changes](https://docs.qmk.fm/#/breaking_changes) for more information.
+
+# Original readme continues
+
 ## Documentation
 
 * [See the official documentation on docs.qmk.fm](https://docs.qmk.fm)