[Keyboard] Add new keyboard Symmetry60 (#7327) Co-Authored-By: James Young <18669334+noroadsleft@users.noreply... Co-Authored-By: James Young <18669334+noroadsleft@users.noreply... Co-Authored-By: James Young <18669334+noroadsleft@users.noreply... Co-Authored-By: James Young <18669334+noroadsleft@users.noreply... Co-Authored-By: James Young <18669334+noroadsleft@users.noreply...