Feature Request: Override TOC transform `maxDepth` parameter in single place

[Justinas-Seskevicius]

In my use case I have multiple markdown files that use TOC transform, some of which have multiple nested headings requiring to specify the maxDepth parameter for those individual files.

It would be great if maxDepth could be provided for all files in a single place, e.g. in markdown.config.js file or via CLI params. This would reduce the need to specify it in every file with nested headings.

[TimPietrusky]

That would be super useful. Initially I thought that you can set the maxDepth (and every other parameter of every transformer) via a config-file, it's not clear at all that you have to provide the config as part of the inline-comment itself.

So please make all the things configurable in one file 🙏