docs: Add usage info for ivhTreeviewMgr and ivhTreeviewBrfs
docs: Add usage info for ivhTreeviewMgr and ivhTreeviewBrfs

michal-husak/angular-ivh-treeview,nbergqui/angular-ivh-treeview,NorthPage/angular-ivh-treeview,JeremyMarshall/angular-ivh-treeview,iVantage/angular-ivh-treeview