[Feature request] Improve default theme appearance

[Mister-Hope]

Clear and concise description of the problem

The appearance of currect default theme is really "aweful" comparing to:

• Vitepress: https://vitepress.vuejs.org/
• Astro: https://docs.astro.build/en/getting-started/
• Docusaurus: https://docusaurus.io/zh-CN/
• ....

Mainly because it lacks some basic function:

• Desktop TOC (Importanted)
• Breadcrumbs (Nice to have)
• Global footer support (Nice to have)
• ...

Any poor appreance in:

• Repo link

• Editlink

• Page nav

• Navbar dropdown

  • adding animation such as http://vuepress-theme-hope.github.io/v2/ (important)

    Current menu is too "Hard"

• Sidebar

  Have to say that the above tool listed all have better outlook

• ...

A good official theme is important for such tools to atract users. People probably won't choose a tool which it's project docs have the poorest appearance.

Suggested solution

Implement the above ones.

Alternative

No response

Additional context

No response

[meteorlxy]

We can consider to rename current theme to theme-classic or so.

[Mister-Hope]

#121