[Feature Request] Add configurable "Mentions" extension

[pratibha1304]

Feature Request

Is your feature request related to a problem? Please describe.
Currently, marked does not natively support GitHub-style mentions (e.g., @user). Users have to write custom regex replacers which can be brittle and often accidentally linkify emails (email@user.com) or mentions inside code blocks.

Describe the solution you'd like
I would like to implement a robust, configurable extension that:

1. Detects @handle syntax.
2. Linkifies it to a configurable baseUrl (default: https://github.com/).
3. Correctly ignores email addresses.
4. Correctly ignores mentions inside inline code ( ) or code blocks.

Describe alternatives you've considered
Using a post-processing regex on the output HTML, but this is error-prone and can break HTML attributes.

[UziTech]

Marked had a template to help create an extension: https://github.com/markedjs/marked-extension-template

You can add it to the known extensions once you publish it 😁👍