Vietnamese Localization (Continued from #2524) (#6564)

* Add Vietnamese localization

* Complete Vietnamese Translations

* Add date localization for Vietnamese

* Fix typos and wording in Vietnamese translation

* Update Vietnamese translation

* Add @vinhphm to Vietnamese translator list

---------

Co-authored-by: CromNguyen <nguyenthietmanh98@gmail.com>

src/locale/helpers.ts

@@ -101,7 +101,7 @@ export function getTranslatorLink(text: string, lang: string): string {
 /**
  * Returns a valid `appLanguage` value from an arbitrary string.
  *
- * Contenxt: post-refactor, we populated some user's `appLanguage` setting with
+ * Context: post-refactor, we populated some user's `appLanguage` setting with
  * `postLanguage`, which can be a comma-separated list of values. This breaks
  * `appLanguage` handling in the app, so we introduced this util to parse out a
  * valid `appLanguage` from the pre-populated `postLanguage` values.
@@ -157,6 +157,8 @@ export function sanitizeAppLanguageSetting(appLanguage: string): AppLanguage {
         return AppLanguage.tr
       case 'uk':
         return AppLanguage.uk
+      case 'vi':
+        return AppLanguage.vi
       case 'zh-CN':
         return AppLanguage.zh_CN
       case 'zh-HK':