Markdown outline and folding support

[StephenSmithwick]

Check for existing issues

• [X] Completed

Describe the feature

Currently the html editor breaks editor content into a hierarchy which can be folded (hidden) by clicking on the carrot(⌄) in the margin.

Can we have a similar capability added to markdown.

The suggested behaviour would be similar to vscode's current solution:

⌄ # Header 1
  Some content
⌄ ## Sub Header
  Some more content
⌄ ## Header 2
  The final content

1. Clicking on carrot beside Header 1 would hide all content below Header 1 up to Header 2
2. Clicking on carrot beside Sub Header would hide content below Sub Header up to Header 2
3. Editing the header line can be edited in place without expanding.
4. Editing the line below the hidden content would re-expand the hidden content

If applicable, add mockups / screenshots to help present your vision of the feature

No response

[notpeter]

More Markdown folding ideas:

• fenced code blocks ```
• entire lists (currently only nested lists can be folded under their parent)
• tables
• definition lists

[aeryncaen]

Would love to see this, especially since I've started using Zed AI for documentation generation.

[opsnull]

I have lots of large markdown files, the outline and folding supporting is great to see。

[KevinSource0]

For navigating lengthy Markdown documents, nested heading breadcrumbs that support multi-level headings are essential, enabling users to jump directly to any heading (as mentioned in https://github.com/zed-industries/zed/issues/21320).

[opsnull]

any planning for this？

[tv42]

See #22703 for likely implementation mechanism.

(I cannot emphasize enough how much I crave this feature! Many of my documents are just unwieldy to scroll back and forth in.)

[github-actions[bot]]

Hi there! 👋 We're working to clean up our issue tracker by closing older bugs that might not be relevant anymore. If you are able to reproduce this issue in the latest version of Zed, please let us know by commenting on this issue, and it will be kept open. If you can't reproduce it, feel free to close the issue yourself. Otherwise, it will close automatically in 14 days. Thanks for your help!

[detjensrobert]

Not stale, latest tag 0.212 still doesn't have header folding.

[miguelraz]

Sorry for the noise, the stalebot upstream went haywire.

Please disregard it.