[Haml] Improve the documentation for doctypes.
[Haml] Improve the documentation for doctypes.

StephanieMak/sass,DanteKaris/sass,hcatlin/sass,srinivashappy/sass,JuanitoFatas/sass,antonifs/sass,tangposmarvin/sass,Andrey-Pavlov/sass,lmetla/sass,danielfein/sass,MetaAshley/sass,jaroot32/sass,nicklima/sass,Galactix/sass,nazar-pc/haml,purcell/haml,cmpereirasi/sass,PMArtz92/sass,baiyanghese/sass,PMArtz92/sass,amitsuroliya/sass,dylannnn/sass,Iamronan/sass,stewx/sass,schneems/sass,uniba/hamldoc_ja,tangposmarvin/haml,keithpitty/haml,sideci-sample/sideci-sample-haml,chriseppstein/sass,stanhu/haml,MetaAshley/sass,briangonzalez/sass,liquidmetal/sass,Anshdesire/sass,ridixcr/sass,zaru/sass,Anshdesire/sass,lmetla/sass,cmpereirasi/sass,StephanieMak/sass,srawlins/sass,concord-consortium/haml,HugoRLopes/sass,Galactix/sass,antonifs/sass,macressler/haml,OrenBochman/sass,keithpitty/haml,ridixcr/sass,amatsuda/haml,srawlins/sass,danielfein/sass,tangposmarvin/haml,HugoRLopes/sass,jaroot32/sass,xzyfer/sass,tangposmarvin/sass,schneems/sass,haml/haml,amitsuroliya/sass,JuanitoFatas/sass,Industrys/sass,Nzaga/sass,tenderlove/sass,dylannnn/sass,chriseppstein/haml,liquidmetal/sass,stanhu/haml,askl56/sass,stewx/sass,nicklima/sass,nickg33/sass,Ahnita/sass,haml/haml,modulexcite/sass,rammy7219/sass,oss-practice/sass,macressler/haml,saper/sass,askl56/sass,saper/sass,nazar-pc/haml,14113/sass,Industrys/sass,zaru/sass,xzyfer/sass,Andrey-Pavlov/sass,rammy7219/sass,Ahnita/sass,hcatlin/sass,nickg33/sass,Nzaga/sass,dg1dd1ngs/haml,OrenBochman/sass,modulexcite/sass,Iamronan/sass,srinivashappy/sass,DanteKaris/sass,haml/haml,chriseppstein/haml,dg1dd1ngs/haml,haml/haml