Remove embedding warning

src/playground/render-interface.jsx

@@ -21,12 +21,6 @@ import Description from '../components/tw-description/description.jsx';
 
 import styles from './interface.css';
 
-if (window !== window.parent) {
-    // Show a warning when trying to embed this page. Users shouldn't do that.
-    // eslint-disable-next-line no-alert
-    alert('You are embedding TurboWarp incorrectly.\n\nGo here for instructions: https://github.com/TurboWarp/scratch-gui/wiki/Embedding');
-}
-
 let announcement = null;
 if (process.env.ANNOUNCEMENT) {
     announcement = document.createElement('p');