Update docs to be clearer
Update docs to be clearer

The examples were for the top level Service builder but the lower level
Provider based version. The higher level one does not accept config yet
(and the object needs to declare which Provider it can work with).

mdarby/fog-core,SpryBTS/fog-core,Temikus/fog-core,fog/fog-core,Ladas/fog-core,higanworks/fog-core