doc: refinements to actionbar docs
doc: refinements to actionbar docs

inclement/kivy,LogicalDash/kivy,bionoid/kivy,akshayaurora/kivy,rnixx/kivy,kivy/kivy,matham/kivy,LogicalDash/kivy,akshayaurora/kivy,akshayaurora/kivy,LogicalDash/kivy,matham/kivy,bionoid/kivy,bionoid/kivy,kivy/kivy,kivy/kivy,LogicalDash/kivy,rnixx/kivy,rnixx/kivy,matham/kivy,inclement/kivy,inclement/kivy,matham/kivy,bionoid/kivy