[FEATURE] Series Display

[kkbt0]

series display

When the series directory is in widescreen, it is displayed above the TOC directory or on the left side of the page.

Useful reference 有价值的参考

like this https://canstand.github.io/compost/posts/shortcodes/

[HEIGE-PCloud]

Maybe we can put it on the left to mimic certain "documentation"-like themes like https://hugo-book-demo.netlify.app/docs/example/table-of-contents/with-toc/

[kkbt0]

看起来很赞
great : )

[CXwudi]

Maybe we can put it on the left to mimic certain "documentation"-like themes like hugo-book-demo.netlify.app/docs/example/table-of-contents/with-toc

Uh, it looks more like yet another menu to me, instead of a series. But I am fine with either way.

[HEIGE-PCloud]

Maybe we can put it on the left to mimic certain "documentation"-like themes like https://hugo-book-demo.netlify.app/docs/example/table-of-contents/with-toc/

I am not quite satisfied with this one either. I think we need a better design before proceeing.