Oak Arduino board v1.1.2

Add the missing folder api taken from the ArduinoCore-API repository.

Full Changelog: 1.1.1...1.1.2

Oak Arduino board v1.1.1

Change directory name as oak, which is the same as defined in boards/txt.

Full Changelog: 1.1.0...1.1.1

Oak Arduino board v1.1.0

Amend some properties in boards.txt

Full Changelog: 1.0.0...1.1.0

Oak Arduino board v1.0.0

1. Arduino Zero variant of SAMD board is used
2. Add a crystalless option to boards.txt

   oak.build.extra_flags=-DCRYSTALLESS -D__SAMD21G18A__ {build.usb_flags}