Add some brief documentation on computed property declarations.
Add some brief documentation on computed property declarations.

re-clone/rivets,GerHobbelt/rivets,nopnop/rivets,altmind/rivets,jccazeaux/rivets,zongkelong/rivets,MishaMykhalyuk/rivets,QAPInt/rivets,mikeric/rivets,GerHobbelt/rivets,altmind/rivets,jccazeaux/rivets,QAPInt/rivets,npmcomponent/mikeric-rivets,re-clone/rivets,GerHobbelt/rivets,mikeric/rivets,benderTheCrime/tiny-rivets,mikeric/rivets,kangax/rivets,nopnop/rivets,zongkelong/rivets,zongkelong/rivets,moneyadviceservice/rivets,nopnop/rivets,jccazeaux/rivets,MishaMykhalyuk/rivets,re-clone/rivets,MishaMykhalyuk/rivets,altmind/rivets,QAPInt/rivets