Fix: #557 documentation has the wrong path for the material theme.   Corrected path to the material theme.
Fix: #557 documentation has the wrong path for the material theme.   Corrected path to the material theme.

stupiduglyfool/ngx-datatable,achimha/ngx-datatable,swimlane/ngx-datatable,swimlane/angular2-data-table,stupiduglyfool/ngx-datatable,janssonav/ngx-datatable,stupiduglyfool/ngx-datatable,swimlane/angular2-data-table,achimha/ngx-datatable,swimlane/ngx-datatable,achimha/ngx-datatable,swimlane/ngx-datatable,swimlane/angular2-data-table,janssonav/ngx-datatable,janssonav/ngx-datatable