Enable multiple language tabs for ScrollyCoding component on docs

[ZYJLiu]

Currently it is not possible to support examples of multiple languages within the same scrollycoding component.

We'll need something like <CodeTabs storage="key"> for <ScrollyCoding> with a tab to toggle between options to support the changes mentioned on #936

[mansiverma897993]

@ZYJLiu can i start working on it , is this issue still didn't solved??

[rajanpanth]

I had a look at how this would fit the current components, and I think the main open question is the authoring API rather than the implementation.

What already exists:

• MultiCode (code.client.tsx) already does storage-backed tabs — it reads group.storage through useStateOrLocalStorage, so cross-component sync and persistence are solved there.
• ScrollyCoding's sticker, though, does not use tabs at all: SelectionSticker renders a file tree (Files/Folder/File) keyed by the code block title, with plain local useState for the selected file, reset per step.

So language tabs are a second axis on top of the existing file axis, and how authors declare it in MDX is the part worth agreeing before any code:

1. Per-step variants — each step declares its language blocks and the tab strip sits above the file tree, or
2. Whole-component variants — <ScrollyCoding storage="lang"> with each step's blocks tagged by language (e.g. a !lang rust flag alongside the existing title flags), so switching swaps the whole file tree for that language.

(2) seems closer to what #936 needed, and it would let the same storage key sync with the MultiCode tabs elsewhere on the page. But it changes what a code block title means inside ScrollyCoding, so it's your call.

@ZYJLiu if you can confirm which shape you want, I'm happy to implement it.