Adding helpers and directives documentation.
Adding helpers and directives documentation.

yonglehou/grunt,r14r/fork_grunt_master,fscherwi/grunt,r14r-work/fork_grunt_master,abraheem/grunt,paladox/grunt,imjerrybao/grunt,pandeysoni/grunt,zackexplosion/grunt,modulexcite/grunt,goodeggs/grunt,yosiazwan/grunt,youmyyou/grunt,eelve/grunt,thecc4re/gruntjs,IveWong/grunt,vojtajina/grunt,felixgrey/grunt,coldrye-collaboration/grunt,ThiagoGarciaAlves/grunt,thejameskyle/grunt,yuhualingfeng/grunt,lkiarest/grunt,JaKXz/grunt,Chhunlong/grunt,rwaldron/grunt,vladikoff/grunt,arosa81/grunt,q310550690/grunt,shama/grunt,paulcbetts/grunt,FeodorFitsner/grunt