Mecanum sample code should bind resetYaw() to a button

[NoahAndrews]

What information should be added?
Unlike the old BNO055 interface, the new IMU interface doesn't reset the yaw value when initialize() is called. This is so that it's possible to have a consistent zero position between autonomous and TeleOp.

Sample code that uses the new IMU should demonstrate the use of this method. For field-centric drive code, it's also a way to get rid of any accumulated yaw drift.

Does it need it's own page? (Yes/No): No

If it needs a page, which section should it be in? If it doesn't, which page should it be under?
https://gm0.org/en/latest/docs/software/tutorials/mecanum-drive.html