Update with information on asMenuItems property of IgxGridPinningActions.
Updated Row Pinning (markdown)
Merge branch 'master' of https://github.com/IgniteUI/igniteui-angular.wiki
applying final changes from discussion
better specifying the difference between pinned/unpinned collections
updating paging rowpinning integration and chip template directive
updating pinning spec with latest as of april 3 information
Add more information on integration scenarios with TreeGrid/HierarchicalGrid specific to their UI.