support new GFM alerts

[matifali]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Problem

Support the new GitHub Alters notation. There were previous requests in #53 and #54.

Note

Useful information that users should know, even when skimming content.

Tip

Helpful advice for doing things better or more easily.

Important

Key information users need to know to achieve their goal.

Warning

Urgent info that needs immediate user attention to avoid problems.

Caution

Advises about risks or negative outcomes of certain actions.

Solution

Have native support for this notation.

Alternatives

An alternative library is remark-github-beta-blockquote-admonitions

[wooorm]

Duplicate of #53

[github-actions]

Hi! Thanks for taking the time to contribute!

Because we treat issues as our backlog, we close duplicates to focus our work and not have to touch the same chunk of code for the same reason multiple times. This is also why we may mark something as duplicate that isn’t an exact duplicate but is closely related.

Thanks,
— bb

[wooorm]

That is not an extension to GFM so doesn’t go here.
Instead, it’s something that would go in rehypejs/rehype-github, or as you mentioned, in another plugin.

[calumk]

For future reference, plugin here : https://github.com/chrisweb/rehype-github-alerts