add en-US directory to the locales directory and move the code from en-US.js file to different files

src/locales/lang/en-US.js

@@ -1,5 +1,7 @@
 import antdEnUS from 'ant-design-vue/es/locale-provider/en_US'
 import momentEU from 'moment/locale/eu'
+import menu from './en-US/menu'
+import setting from './en-US/setting'
 
 const components = {
   antLocale: antdEnUS,
@@ -7,39 +9,13 @@ const components = {
   momentLocale: momentEU
 }
 
-const locale = {
+export default {
   'message': '-',
-  'menu.home': 'Home',
-  'menu.dashboard': 'Dashboard',
-  'menu.dashboard.analysis': 'Analysis',
-  'menu.dashboard.monitor': 'Monitor',
-  'menu.dashboard.workplace': 'Workplace',
 
   'layouts.usermenu.dialog.title': 'Message',
   'layouts.usermenu.dialog.content': 'Do you really log-out.',
 
-  'app.setting.pagestyle': 'Page style setting',
-  'app.setting.pagestyle.light': 'Light style',
-  'app.setting.pagestyle.dark': 'Dark style',
-  'app.setting.pagestyle.realdark': 'RealDark style',
-  'app.setting.themecolor': 'Theme Color',
-  'app.setting.navigationmode': 'Navigation Mode',
-  'app.setting.content-width': 'Content Width',
-  'app.setting.fixedheader': 'Fixed Header',
-  'app.setting.fixedsidebar': 'Fixed Sidebar',
-  'app.setting.sidemenu': 'Side Menu Layout',
-  'app.setting.topmenu': 'Top Menu Layout',
-  'app.setting.content-width.fixed': 'Fixed',
-  'app.setting.content-width.fluid': 'Fluid',
-  'app.setting.othersettings': 'Other Settings',
-  'app.setting.weakmode': 'Weak Mode',
-  'app.setting.copy': 'Copy Setting',
-  'app.setting.loading': 'Loading theme',
-  'app.setting.copyinfo': 'copy success，please replace defaultSettings in src/models/setting.js',
-  'app.setting.production.hint': 'Setting panel shows in development environment only, please manually modify'
-}
-
-export default {
   ...components,
-  ...locale
+  ...menu,
+  ...setting
 }

src/locales/lang/en-US/menu.js

@@ -0,0 +1,8 @@
+export default {
+    'menu.welcome': 'Welcome',
+    'menu.home': 'Home',
+    'menu.dashboard': 'Dashboard',
+    'menu.dashboard.analysis': 'Analysis',
+    'menu.dashboard.monitor': 'Monitor',
+    'menu.dashboard.workplace': 'Workplace'
+}

src/locales/lang/en-US/setting.js

@@ -0,0 +1,22 @@
+export default {
+    'app.setting.pagestyle': 'Page style setting',
+    'app.setting.pagestyle.light': 'Light style',
+    'app.setting.pagestyle.dark': 'Dark style',
+    'app.setting.pagestyle.realdark': 'RealDark style',
+    'app.setting.themecolor': 'Theme Color',
+    'app.setting.navigationmode': 'Navigation Mode',
+    'app.setting.content-width': 'Content Width',
+    'app.setting.fixedheader': 'Fixed Header',
+    'app.setting.fixedsidebar': 'Fixed Sidebar',
+    'app.setting.sidemenu': 'Side Menu Layout',
+    'app.setting.topmenu': 'Top Menu Layout',
+    'app.setting.content-width.fixed': 'Fixed',
+    'app.setting.content-width.fluid': 'Fluid',
+    'app.setting.othersettings': 'Other Settings',
+    'app.setting.weakmode': 'Weak Mode',
+    'app.setting.copy': 'Copy Setting',
+    'app.setting.loading': 'Loading theme',
+    'app.setting.copyinfo': 'copy success，please replace defaultSettings in src/models/setting.js',
+    'app.setting.production.hint': 'Setting panel shows in development environment only, please manually modify'
+
+}