Just noticed strikethrough text handling was not implemented for the
following:

Chat

![image](https://github.com/zed-industries/zed/assets/53836821/ddd98272-d4d4-4a94-bd79-77e967f3ca15)

Markdown Preview

![image](https://github.com/zed-industries/zed/assets/53836821/9087635c-5b89-40e6-8e4d-2785a43ef318)

Code Documentation

![image](https://github.com/zed-industries/zed/assets/53836821/5ed55c60-3e5e-4fc2-86c2-a81fac7de038)

It looks like there are three different markdown parsing/rendering
implementations, might be worth to investigate if any of these can be
combined into a single crate (looks like a lot of work though).

Release Notes:

- Added support for rendering strikethrough text in markdown elements