init ui in user preferred lang on 1st run (#28254)

editor/js/Config.js

@@ -2,8 +2,12 @@ function Config() {
 
 	const name = 'threejs-editor';
 
+	const userLanguage = navigator.language.split( '-' )[ 0 ];
+
+	const suggestedLanguage = [ 'fr', 'ja', 'zh' ].includes( userLanguage ) ? userLanguage : 'en';
+
 	const storage = {
-		'language': 'en',
+		'language': suggestedLanguage,
 
 		'autosave': true,