doc: fix layout in graphics/xgl.pyx
doc: fix layout in graphics/xgl.pyx

jkankiewicz/kivy,rnixx/kivy,matham/kivy,bionoid/kivy,Cheaterman/kivy,matham/kivy,janssen/kivy,LogicalDash/kivy,jegger/kivy,manthansharma/kivy,Cheaterman/kivy,kivy/kivy,kivy/kivy,bionoid/kivy,kivy/kivy,jegger/kivy,KeyWeeUsr/kivy,KeyWeeUsr/kivy,jkankiewicz/kivy,akshayaurora/kivy,jkankiewicz/kivy,bionoid/kivy,LogicalDash/kivy,tony/kivy,rnixx/kivy,Cheaterman/kivy,autosportlabs/kivy,bionoid/kivy,jegger/kivy,janssen/kivy,inclement/kivy,inclement/kivy,KeyWeeUsr/kivy,janssen/kivy,autosportlabs/kivy,KeyWeeUsr/kivy,autosportlabs/kivy,janssen/kivy,LogicalDash/kivy,matham/kivy,tony/kivy,inclement/kivy,akshayaurora/kivy,manthansharma/kivy,matham/kivy,manthansharma/kivy,jegger/kivy,Cheaterman/kivy,manthansharma/kivy,tony/kivy,rnixx/kivy,jkankiewicz/kivy,LogicalDash/kivy,akshayaurora/kivy