Bot keyboard
fixes #31 (closed)
implements only RelplyMarkupShowKeyboard (it ignores oneTime
and isPersonal
properties atm) and ReplyMarkupRemoveKeyboard (hides the keyboard when there's no active keyboard)
ReplyMarkupForceReply still needs to be implemented
ReplyMarkupInlineKeyboard isn't truly part of the bot keyboard, it's the keyboard displayed under some messages (typically from bots), not implemented.