* Add support for building against ChibiOS svn/trunk.
* Swap to 21.6.x
* Update to latest branch revision as released version is broken.
* Updated configs.
* Conf updates.
* Updated ChibiOS
* Convert STM32L422 to actual L422 ChibiOS platform.
* Downgrade to 20.3.4 as ChibiOS 21.6.x is being aborted.
* Rollback L422-based boards.
* Update ChibiOS, ChibiOS-Contrib.
* Add instructions.
* Wrong remote name
* Explicit version tag.
* Add link to procedure on the breaking changes page.
Nick Brassel