Takes out documentation for `Merit::Badge.last_granted`.
Takes out documentation for `Merit::Badge.last_granted`.

It should live in a wiki page, outside of merit's repository. See:
https://github.com/tute/merit/issues/111#issuecomment-34876788
https://github.com/tute/merit/issues/138#issuecomment-35232823

woopasoft/merit,woopasoft/merit,michael-gabenna/merit,raderj89/merit,pablobfonseca/merit,woopasoft/merit,iagopiimenta/merit,caiqinghua/merit,hw676018683/merit,caiqinghua/merit,michael-gabenna/merit,pablobfonseca/merit,pablobfonseca/merit,iagopiimenta/merit,hw676018683/merit,raderj89/merit,hw676018683/merit,caiqinghua/merit,iagopiimenta/merit,raderj89/merit,michael-gabenna/merit