not working properly with doom emacs's workspace session store feature.

it seems this problem cause from vue-mode use mmm-mode.
when workspace store session, only store sub-mode of vue-mode.

ex) when vue[TypeScript] => recognize buffer is only in typescript-mode
ex) when vue[Stylus] => recognize buffer is only in stylus-mode
ex) when vue[Pug] => recognize buffer is only in pug-mode

in vue-mode.


try to store sessions.


look at stored session file.

```lisp
((def-persp
"DONNA-WEB" ((def-buffer "SearchInfoRow.vue" "/Users/jjpark78/Development/JJSOFT/donna/DONNA-WEB/src/components/search/SearchInfoRow.vue"
typescript-mode)
```

it stored as typescript-mode.

使用 vue-mode、mmm-mode 和 Doom Emacs 的 workspace session store 重現此問題，然後檢查報告中顯示的已儲存 session 項目。確定為什麼 vue buffer 只會被記錄為 typescript-mode、stylus-mode 或 pug-mode；完成的標準是還原 workspace 後仍保留 vue-mode buffer 的識別，而不只是其子模式。

由索引模型根據 Issue 內容生成。