disallow shape selection during creation (#449)

src/index.tsx

@@ -299,8 +299,7 @@ export class App extends React.Component<{}, AppState> {
       !event.shiftKey &&
       !event.altKey &&
       !event.metaKey &&
-      (this.state.draggingElement === null ||
-        this.state.elementType !== "selection")
+      this.state.draggingElement === null
     ) {
       this.setState({ elementType: findShapeByKey(event.key) });
     } else if (event[KEYS.META] && event.code === "KeyZ") {