disable right-click brushing

src/index.ts

@@ -414,9 +414,9 @@ abstract class ChartwerkPod<T extends Serie, O extends Options> {
     // TODO: refactor
     switch(key) {
       case KeyEvent.MAIN:
-        return () => !d3.event.shiftKey;
+        return () => !d3.event.shiftKey && !d3.event.button;
       case KeyEvent.SHIFT:
-        return () => d3.event.shiftKey;
+        return () => d3.event.shiftKey && !d3.event.button;
       default:
         throw new Error(`Unknown type of KeyEvent: ${key}`);
     }