Fix the calls to getGlobalKonva() inside the current code base

Following the recent migration to TypeScript, getGlobalKonva()
returns undefined (as glob.Konva was not set) when using konva.js
or konva.min.js inside a web application running in a browser.
This change works around the situation by explicitly setting the
Konva property on the glob object.

src/index.ts

@@ -50,4 +50,6 @@ Konva.angleDeg = true;
  */
 Konva.showWarnings = true;
 
+Konva.glob.Konva = Konva;
+
 export default KonvaInternals;