Move markdown-it types for options export

[brendankenny]

Hi!

First, thanks so much for creating markdown-it-math.

Second: I was just updating a project of mine to using typescript 7 and MarkdownIt and Token got flagged as unresolved in the dependency lib check.

You can repro the error in markdown-it-math itself if you update to typescript@7, but I didn't do that here in case you aren't ready for the switch (and to be sure the change still works with typescript 6). Happy to add it to the PR if that's helpful though.

It's interesting that typescript 6 doesn't seem to be bothered by them being any in options.js (though they are properly typed in plugin.js), but typescript 7's jsdoc checking is a bit stricter, so something shifted. Looking at the code, it looks like this change may have been what you intended anyways, but the two typedefs didn't move to options.js when the @callback declaration moved there.

Thanks again!

[runarberg]

Thanks. I will probably update all dependencies (including typescript 7) and make a release later this week

[runarberg]

Released: v6.0.1. Thanks for your help.