added/fixed headers k-n

https://github.com/borisyankov/DefinitelyTyped/issues/1570

ng-grid/ng-grid.d.ts

@@ -1,6 +1,6 @@
 // Type definitions for ng-grid 
 // Project: http://angular-ui.github.io/ng-grid/
-// Initial definitions by: Ken Smith <https://github.com/smithkl42>
+// Definitions by: Ken Smith <https://github.com/smithkl42>
 // DefinitelyTyped: https://github.com/borisyankov/DefinitelyTyped
 
 // These are very definitely preliminary. Please feel free to improve.
@@ -188,4 +188,4 @@ declare module ngGrid {
         /** currentPage: the uhm... current page. */
         currentPage?: number;
     }
-}
+}