Rewrite comment to reflect what beginDraw and endDraw exist for
Rewrite comment to reflect what beginDraw and endDraw exist for

jaredly/processing-js,jeresig/processing-js,guazipi/processing-js,jaredly/processing-js,baiyanghese/processing-js,guazipi/processing-js,jeresig/processing-js,kevinb7/processing-js,baiyanghese/processing-js,kevinb7/processing-js