doc(showdown.js): add source documentation for showdown's api
doc(showdown.js): add source documentation for showdown's api

digideskio/showdown,coolroad/showdown,OMGgogong/showdown,stevemao/showdown,showdownjs/showdown,phw/showdown,juanonsoftware/showdown,pazof/showdown,xinshitn/showdown,bsansouci/showdown,coolroad/showdown,pazof/showdown,axter/showdown,yaniswang/showdown,xinshitn/showdown,twitwi/showdown,webutilz/showdown,axter/showdown,alazyer/showdown,juanonsoftware/showdown,NichenLg/showdown,bsnizek/showdown,yaniswang/showdown,NichenLg/showdown,digideskio/showdown,alazyer/showdown,stevemao/showdown,twitwi/showdown,snegovick/showdown,bsnizek/showdown,webutilz/showdown,snegovick/showdown,showdownjs/showdown,phw/showdown,bsansouci/showdown,OMGgogong/showdown