fix demo pod

demo/demo_pod.ts

@@ -54,6 +54,7 @@ class DemoPod extends ChartwerkPod<Serie, Options> {
   onMouseMove(): void {}
   onMouseOver(): void {}
   onMouseOut(): void {}
+  onMouseClick(): void {}
   renderSharedCrosshair(values): void {}
   hideSharedCrosshair(): void {}
 }