feat: adding VTCodeGroup component to the @vue/theme (#46)

[JessicaSachs]

Resolves #46

Adds a VTCodeGroup component to replace https://github.com/vuejs/docs/blob/main/src/guide/scaling-up/TestingApiSwitcher.vue

Also @kiaking it fixes the mobile responsive issues you saw with the original implementation. To test it, I replaced the custom component I pasted above locally. I was looking for a way to demo/test out the component in this repo. Is there any infra for that?

demo.mov

[JessicaSachs]

BTW (just curious)... why aren't we using scoped *styles in this repo?

[kiaking]

Wonderful work! 🙌

I was looking for a way to demo/test out the component in this repo. Is there any infra for that?

I think demo folder is used for this purpose 👍

BTW (just curious)... why aren't we using scoped slots in this repo?

Well we do in vitepress folder. The reason we use external css in core is that because at the beginning of this repo, we thought it might be nice to be able to use core component or styles without using Vue component.

Like when we have pure HTML only stuff, we can reuse the same css (like bootstrap css). However, later on, we decided this repo to be Vue website exclusive, I'm thinking to put those css into component with scoped css 😅 And also merge core folder and vitepress folder.

[JessicaSachs]

I think demo folder is used for this purpose 👍

Yeah I had issues with the demo folder because it doesn't pull in all of the code block styles, so when I went to test this, the CodeGroup component didn't look great. Nbd though.

Thx for the explanation about the css. I was so confused about why we wouldn't use scoped styles. Thought there must've been a reason 😂

LMK if you need anything else 🎉

[yyx990803]

New theme has been published and updated in vuejs/docs so feel free to open a PR there to refactor the usage :)