markdown-it v14 is not supported

[vadjs]

Good afternoon team,

Usage of @diplodoc/transform causes errors. It's because the markdown-it v14 moved to ESM Modules bundle.
I think it makes sense to update markdown-it to version 14 in this package.

[3y3]

ESM is painfull.

We prepare manifest for next major version of transform. And publish in at 02.10.2024.
#519