Rename or remove addMarkdownHighlighter

[Snapstromegon]

Is your feature request related to a problem? Please describe.

In general the add*() functions of the eleventy config are non-destructive if possible. addMarkdownHightlighter() on the other hand behaves like the set*() functions.

Also this function IMO is no longer necessary, since there are other, better and better documented options in eleventy.

Function in code:
https://github.com/11ty/eleventy/blob/main/src/UserConfig.js#L170

Describe the solution you'd like

I would recommend to either remove this function completely with the next major version, or to rename it to setMarkdownHighlighter() and add documentation for it.

Describe alternatives you've considered

Not changing anything is possible, but leaves this in a weird state.

Additional context

No response

[Subham-KRLX]

Hi! I’d like to work on this issue. May I take it up?

[mohammedadelabu]

Hi! I’d like to work on this issue. Can I pick it up?

[mohammed-hassan-angular-frontend-fcmb]

Hi! I would like to work on this issue. May I take it up?

[zachleat]

Hmm, I wouldn’t consider this part of the public userland API but it does exist and we’ll probably just leave it as-is for backwards compatibility.

For competeness, it is used by the syntax highlighter plugin v5 and will be removed by v6 11ty/eleventy-plugin-syntaxhighlight#100 so we’ll probably wait awhile after v6 is released to discuss removing it from core at that point