Add plugin manual and translation template.

(by DeepL Translator)

In this update of the plugin resources, I removed the previous manual and replaced it with the HackMD platform as the new online manual.

In addition, since the author does not have much time to translate the plug-in himself, the author has made the plugin template for translation (NekoGakuen_MulitLanguage_TransMod.js) available to other people who want to translate it, so that they can use it directly without modifying the plugin, and those who can understand the details of the plugin can use the plugin template provided by the author to translate it.

(原文)

本次的插件資源的更新部分，我將之前的使用手冊移除，並且改以 HackMD 平台作為新的線上手冊。

此外，由於作者本身沒有很多時間做插件翻譯，所以作者公開 翻譯用插件模板(NekoGakuen_MulitLanguage_TransMod.js) 給其他想翻譯的人方便翻譯好直接使用，而不用再特地修改本插件，看得懂插件細節的人，再使用作者提供的插件模板進行翻譯。