Update documentation on release cadence
Signed-off-by:Felix Thomasmathibalan <felixjohnny.thomasmathibalan@arm.com> Approved-by:
Emil Ohlsson <emil.ohlsson@arm.com>
Signed-off-by:Felix Thomasmathibalan <felixjohnny.thomasmathibalan@arm.com> Approved-by:
Emil Ohlsson <emil.ohlsson@arm.com>