keychron_qmk_firmware/docs/adding_features_to_qmk.md

If you have an idea for a custom feature or extra hardware connection, we'd love to accept it into QMK! These are generally done via [pull request](https://github.com/qmk/qmk_firmware/pulls) after forking, and here are some things to keep in mind when creating one:

* **Disable by default** - memory is a pretty limited on most chips QMK supports, and it's important that current keymaps aren't broken, so please allow your feature to be turned **on**, rather than being turned off. If you think it should be on by default, or reduces the size of the code, [open an issue](https://github.com/qmk/qmk_firmware/issues) for everyone to discuss it!
* **Compile locally before submitting** - hopefully this one is obvious, but things need to compile! Our Travis system will catch any issues, but it's generally faster for you to compile a few keyboards locally instead of waiting for the results to come back.
* **Consider subprojects and different chip-bases** - there are several keyboards that have subprojects that have allow for slightly different configurations, and even different chip-bases. Try to make a feature supported in ARM and AVR, or automatically disabled in one that doesn't work.
* **Explain your feature** - submitting a markdown write-up of what your feature does with your PR may be needed, and it will allow a collaborator to easily copy it into the wiki for documentation (after proofing and editing).
* **Don't refactor code** - to maintain a clear vision of how things are laid out in QMK, we try to plan out refactors in-depth, and have a collaborator make the changes. If you have an idea for refactoring, or suggestions, [open an issue](https://github.com/qmk/qmk_firmware/issues).