Improve example lang. (#990)

examples/components/header.vue

@@ -200,6 +200,7 @@
     methods: {
       switchLang(targetLang) {
         if (this.lang === targetLang) return;
+        localStorage.setItem('ELEMENT_LANGUAGE', targetLang);
         this.$router.push(this.$route.path.replace(this.lang, targetLang));
       }
     },

examples/route.config.js

@@ -85,12 +85,18 @@ langs.forEach(lang => {
   route = route.concat(generateMiscRoutes(lang.lang));
 });
 
+let userLanguage = localStorage.getItem('ELEMENT_LANGUAGE') || window.navigator.language;
+let defaultPath = '/en-US';
+if (userLanguage.indexOf('zh-') !== -1) {
+  defaultPath = '/zh-CN';
+}
+
 route = route.concat([{
   path: '/',
-  redirect: '/zh-CN'
+  redirect: defaultPath
 }, {
   path: '*',
-  redirect: '/zh-CN'
+  redirect: defaultPath
 }]);
 
 export default route;