Keep en lang always imported

docs/modules/I18n.md

@@ -23,8 +23,8 @@ By default, the editor includes only the English language, if you need other lan
 
 ```js
 import grapesjs from 'grapesjs';
-import en from 'grapesjs/locale/en';
 import it from 'grapesjs/locale/it';
+import tr from 'grapesjs/locale/tr';
 
 const editor = grapesjs.init({
   ...
@@ -32,7 +32,7 @@ const editor = grapesjs.init({
     // locale: 'en', // default locale
     // detectLocale: true, // by default, the editor will detect the language
     // localeFallback: 'en', // default fallback
-    messages: { en, it },
+    messages: { it, tr },
   }
 });
 ```

src/i18n/index.js

@@ -6,9 +6,7 @@
  *    locale: 'en',
  *    localeFallback: 'en',
  *    messages: {
- *      en: {
- *       hello: 'Hello',
- *      },
+ *      it: { hello: 'Ciao', ... },
  *      ...
  *    }
  *  }
@@ -66,7 +64,14 @@ export default () => {
      * @private
      */
     init(opts = {}) {
-      this.config = { ...config, ...opts };
+      this.config = {
+        ...config,
+        ...opts,
+        messages: {
+          ...config.messages,
+          ...(opts.messages || {})
+        }
+      };
 
       if (this.config.detectLocale) {
         this.config.locale = this._localLang();

test/specs/i18n/index.js

@@ -42,6 +42,13 @@ describe('I18n', () => {
       expect(obj.getLocale()).toBe(locale);
     });
 
+    test('English always imported', () => {
+      obj.init({
+        messages: { it: {} }
+      });
+      expect(Object.keys(obj.getMessages())).toEqual(['en', 'it']);
+    });
+
     test('setLocale and getLocale methods', () => {
       const localeBefore = obj.getLocale();
       const localeNew = `${localeBefore}2`;