* Remove some deadcode
* Use 2-word name for CSS class names
* Remove "gt-*" rules for sanitizer
The UI doesn't change much.
(cherry picked from commit 66902d89e567ab1ae6dfb828636999c61ff0149e)
- Follows https://github.com/go-gitea/gitea/pull/29121
When I implemented alert blocks I was always testing the markdown in
issue comments. I used `<br />` for line breaks and it looked good. I
have since learned that the markdown on README files doesn't allow these
tags. So a comment with
```md
> [!NOTE]
> If you're interested in using our APIs, we have experimental support with [documentation](https://try.gitea.io/api/swagger).
```
looked like this in a comment

but looked like this in a README

So I changed how we render the alert block by having the alert itself
have a dedicated paragraph, so line breaks happen naturally between
paragraphs.




---------
Signed-off-by: Yarden Shoham <git@yardenshoham.com>
Co-authored-by: silverwind <me@silverwind.io>
This lifts out the GitHub callout transformer from
`modules/markup/markdown/goldmark.go` to `callout/github.go`.
While there, clean up the transformer code:
- Use a map to look up supported callout types, rather than a regexp.
- Allow the callout type to be in any case, rather than just uppercase.
- Simplified `.Segment.Value()` to `.Text()`.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>