Remove notice about `develop`.

readme.md

@@ -1,7 +1,3 @@
-# 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.
-
 # Quantum Mechanical Keyboard Firmware
 
 [![Current Version](https://img.shields.io/github/tag/qmk/qmk_firmware.svg)](https://github.com/qmk/qmk_firmware/tags)