Added contribution section and changed VERSION_NUMBER in install commands
Added contribution section and changed VERSION_NUMBER in install commands

newa34/lokki-android,oneb/lokki-android,suleymanakbas91/lokki-android,TheSoftwareFactory/lokki-android,olzraiti/lokki-android,Kapoor-uh/lokki-android,sandeepgithubrepo/lokki-android,DocV/lokki-android,eemihauk/lokki-android,soumyaijteee/lokki-android,Grandi/lokki-android,iatarah/lokki-android,akkashaider/lokki-android,ffagerho/lokki-android