feat(localization): Add en/vi language

Task.md

@@ -0,0 +1,31 @@
+- Goal:
+Add new localization (i18n) to my website using the Internationalization plugin of Umi Max so that users can switch between Vietnamese and English.
+
+- Tasks for you:
+
+1. Create full base setup for i18n in Umi Max, including:
+
+    + Required configuration in config/config.ts
+
+    + Folder structure for locales
+
+    + Base translation files (vi-VN.ts, en-US.ts)
+
+    + Any needed runtime or app-level configuration
+
+2. Provide sample code for:
+
+    + Using i18n inside components (useIntl, <FormattedMessage />, etc.)
+
+    + Creating a language switcher component
+
+3. Write a clear usage guide explaining:
+
+    + Where to place all files
+
+    + How to import and use translations
+
+    + How to switch languages at runtime
+
+Make sure all examples are valid for Umi Max (Umi 4.5.0). Checked task you complete
+