doc: Mark API as stable for release
doc: Mark API as stable for release

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

hallyn/lxd,ollie314/lxd,lxc/lxd,chrisglass/lxd,atxwebs/lxd,ollie314/lxd,stgraber/lxd,mjeanson/lxd,lxc/lxd,akshaykarle/lxd,pcdummy/lxd,erikmack/lxd,Skarlso/lxd,techtonik/lxd,jsavikko/lxd,hallyn/lxd,Skarlso/lxd,erikmack/lxd,mjeanson/lxd,stgraber/lxd,georghopp/lxd,stgraber/lxd,georghopp/lxd,jsavikko/lxd,stgraber/lxd,hallyn/lxd,akshaykarle/lxd,techtonik/lxd,lxc/lxd,atxwebs/lxd,lxc/lxd,atxwebs/lxd,atxwebs/lxd,pcdummy/lxd,ollie314/lxd,georghopp/lxd,akshaykarle/lxd,stgraber/lxd,mjeanson/lxd,lxc/lxd,lxc/lxd,pcdummy/lxd,stgraber/lxd,chrisglass/lxd,chrisglass/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,jsavikko/lxd,erikmack/lxd,stgraber/lxd,techtonik/lxd,hallyn/lxd,Skarlso/lxd,Skarlso/lxd