Change keywords in IMode to any

The keywords key can be represented by either a string or an object, see:

http://highlightjs.readthedocs.org/en/latest/language-guide.html#keywords

highlightjs/highlightjs.d.ts

@@ -96,7 +96,7 @@ declare module "highlight.js"
 
 		export interface IMode extends IModeBase
 		{
-			keywords?: string;
+			keywords?: any;
 			contains?: IMode[];
 		}