runtime(menu): Fix "Open &Tab..." CJK translations to have shortcut key (#13031)

Previous PR (#12993) fixed localization files to point to "Open &Tab..."
but they didn't add the shortcut key to the translated names. This adds
the shortcut keys to the CJK translations in the form of "(&T)".

Note that this doesn't add the shortcut to latin script languages like
Czech. These types of translated names tend to also localize the
shortcut keys for them to make sense to the user and it's up to each
translator to decide how to do so. CJK translations tend to just take
the English key directly since it doesn't make sense to have a localized
shortcut key in general.


Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/lang/menu_ja_jp.utf-8.vim

@@ -39,7 +39,7 @@ let g:menutrans_help_dialog = "ヘルプを検索したいコマンドもしく
 menutrans &File				ファイル(&F)
 menutrans &Open\.\.\.<Tab>:e		開く(&O)\.\.\.<Tab>:e
 menutrans Sp&lit-Open\.\.\.<Tab>:sp	分割して開く(&L)\.\.\.<Tab>:sp
-menutrans Open\ &Tab\.\.\.<Tab>:tabnew	タブページで開く<Tab>:tabnew
+menutrans Open\ &Tab\.\.\.<Tab>:tabnew	タブページで開く(&T)<Tab>:tabnew
 menutrans &New<Tab>:enew		新規作成(&N)<Tab>:enew
 menutrans &Close<Tab>:close		閉じる(&C)<Tab>:close
 menutrans &Save<Tab>:w			保存(&S)<Tab>:w