included method definition for onrendered event which provides the rendered canvas element

html2canvas/html2canvas.d.ts

@@ -37,6 +37,8 @@ declare module Html2Canvas {
         /** Whether to attempt to load cross-origin images as CORS served, before reverting back to proxy. */
         useCORS?: boolean;
 
+        /** Callback providing the rendered canvas element after rendering */
+        onrendered?(canvas: HTMLElement): void;
     }
 }