Updated README to describe included and excluded functionality
Updated README to describe included and excluded functionality

gdseller/PhantomCSS,aeharding/PhantomCSS,johnhunter/PhantomCSS,smrq/PhantomCSS,istr/PhantomCSS,smrq/PhantomCSS,stefanteixeira/exemplo-phantomcss-palestra,tpgmartin/PhantomCSS,gdseller/PhantomCSS,tpgmartin/PhantomCSS,shakyShane/css-reg-test,Huddle/PhantomCSS,tazminweb/PhantomCSS,marijer/phantomcss_test,Huddle/PhantomCSS,johnhunter/PhantomCSS,aeharding/PhantomCSS,shakyShane/css-reg-test,tazminweb/PhantomCSS,istr/PhantomCSS,stefanteixeira/exemplo-phantomcss-palestra