Allow `caption` for code fences

[asymmetric]

Describe the feature you'd like to request

I'd like for fenced code blocks to support the caption attribute.

Right now if I want captions on code blocks, I have to use ```{code-block} $LANG` form, which has two issues:

• no syntax highlighting in most editors, since they don't know about this form
• the myst_number_code_blocks directive doesn't apply (this might be a separate bug)

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

[welcome[bot]]

Thanks for opening your first issue here! Engagement like this is essential for open source projects! :hugs:
If you haven't done so already, check out EBP's Code of Conduct. Also, please try to follow the issue template as it helps other community members to contribute more effectively.
If your issue is a feature request, others may react to it, to raise its prominence (see Feature Voting).
Welcome to the EBP community! :tada: