Add document explaining API guidelines process
Add document explaining API guidelines process

ViktorHofer/corefx,zhenlan/corefx,wtgodbe/corefx,wtgodbe/corefx,shimingsg/corefx,mmitche/corefx,ptoonen/corefx,ravimeda/corefx,Ermiar/corefx,shimingsg/corefx,ViktorHofer/corefx,axelheer/corefx,Jiayili1/corefx,Ermiar/corefx,Jiayili1/corefx,fgreinacher/corefx,ptoonen/corefx,Ermiar/corefx,ericstj/corefx,mmitche/corefx,mmitche/corefx,ericstj/corefx,shimingsg/corefx,fgreinacher/corefx,BrennanConroy/corefx,ptoonen/corefx,axelheer/corefx,Jiayili1/corefx,mmitche/corefx,ViktorHofer/corefx,mmitche/corefx,ravimeda/corefx,fgreinacher/corefx,BrennanConroy/corefx,shimingsg/corefx,Jiayili1/corefx,ptoonen/corefx,shimingsg/corefx,axelheer/corefx,wtgodbe/corefx,ericstj/corefx,ravimeda/corefx,mmitche/corefx,fgreinacher/corefx,zhenlan/corefx,ravimeda/corefx,Ermiar/corefx,ViktorHofer/corefx,zhenlan/corefx,ericstj/corefx,ericstj/corefx,ptoonen/corefx,ViktorHofer/corefx,Ermiar/corefx,ericstj/corefx,zhenlan/corefx,ptoonen/corefx,Jiayili1/corefx,Jiayili1/corefx,axelheer/corefx,axelheer/corefx,BrennanConroy/corefx,shimingsg/corefx,zhenlan/corefx,mmitche/corefx,wtgodbe/corefx,ericstj/corefx,Jiayili1/corefx,ravimeda/corefx,ravimeda/corefx,wtgodbe/corefx,ravimeda/corefx,zhenlan/corefx,zhenlan/corefx,Ermiar/corefx,ViktorHofer/corefx,axelheer/corefx,Ermiar/corefx,ViktorHofer/corefx,wtgodbe/corefx,shimingsg/corefx,wtgodbe/corefx,ptoonen/corefx