add docs about :inherit.
add docs about :inherit.

bolshakov/reform,joealba/reform,eljojo/reform,francirp/reform,mipearson/reform,halan/reform,gdott9/reform,halan/reform,mipearson/reform,apotonick/reform,francirp/reform,trailblazer/reform,prosanelli/reform,bolshakov/reform,eljojo/reform,Miralaw/reform,swifthand/reform,Miralaw/reform,swifthand/reform,joealba/reform,prosanelli/reform,simonc/reform