docs: Update wrong import for the locale prop, update migration guide (fixes #1174)

Author: Jasenkoo

docs/migration/from-v11.md

@@ -224,6 +224,14 @@ Prop type is changed, and no longer provides arguments if a function is provided
 
 Locale prop type is changed, and will now only accept `date-fns` `Locale` object.
 
+If you don't have it in the project, you can install it via `npm install date-fns`
+
+and then import it:
+
+```ts
+import { znCh } from 'date-fns/locale'
+```
+
 ### `disable-month-year-select`
 
 This prop is renamed to `hide-month-year-select`

docs/props/localization/index.md

@@ -32,7 +32,7 @@ Based on specified formats in [`formats`](/props/formatting/#formats) prop, the
 
 <script setup>
   import { VueDatePicker } from "@vuepic/vue-datepicker"
-  import { zhCn } from "@vuepic/vue-datepicker/locale"
+  import { zhCn } from "date-fns/locale"
   import { ref } from 'vue';
 
   const date = ref(new Date());