Optimize for Simplified Chinese translation (#48)

* feat: Optimize for Simplified Chinese translation

* fix: fix language pack index for zhcn

frontend/src/locales/index.ts

@@ -1,7 +1,7 @@
 import { createI18n } from 'vue-i18n'
 import en from './en'
 import fa from './fa'
-import ch from './ch'
+import zhcn from './zhcn'
 
 
 export const i18n = createI18n({
@@ -11,12 +11,12 @@ export const i18n = createI18n({
   messages: {
     en,
     fa,
-    ch
+    zhcn
   },
 })
 
 export const languages = [
   { title: 'English', value: 'en' },
-  { title: '简体中文', value: 'ch' },
   { title: 'فارسی', value: 'fa' },
+  { title: '简体中文', value: 'zhcn' },
 ]