feat: add new listr function with add capability

[chamabreu]

BREAKING CHANGE: It is now possible to give a folder as file argument e.g.: md2pdf $(pwd)

This works recursive. The watcher will listen for all add and change events in all subfolders, but only for markdown files.

For compatibility, a legacy function is kept alive, to handle multiple input paths, like ./**/*.md, so the old cli app works like before.

[chamabreu]

Hi,
related to #137 , this is my example how this could be implemented.

Refactored on the way a few things.

Would be nice, if we can pull this in.
If not, no Problem, I will work then only on my fork.

[simonhaenisch]

Thanks a lot for this! I've had a quick look, and it's a lot of changes overall... finding it a bit hard to follow through. Would have been nice if you could have split it into separate commits for the individual changes so it would be easier to understand and reason about each change 🤓

Anyway, one thing I would like to propose is to allow setting a folder with a -r/--recursive flag instead, so maybe this could get away as a non-breaking change (:

But not sure I would go ahead with this PR as-is, e.g. I find the "convert factory" part a bit too abstract.

[chamabreu]

Thanks for the feedback.

I implemented the convertFactory for that it is not more necessary to push all the configs and args around.
But maybe this could be overpowered now, I have to review it myself.

If you are willing to merge it, if I develop it further to your coding style, I will do.
If you dont want this feature in your repo, I will stick to my fork.

Just tell me.
I would do:
Refactor the factoryFunction (remove)

Dunno if its necessary to add that -r flag.
At the state now, it is not really breaking, is it?
Because i kept the posibility to pass a glob pattern.

But I had the idea, that a user could give a folder, and set the recursive depth.
Maybe this and the -r flag could go in a next PR/Feature.

[chamabreu]

Pushed a commit where convertFactory is removed.

I would need to dig deeper in CLI flags, to get to know how to implement the -r flag.
Is this mandatory for you?
I think, because the program works like before, with the ./*.md and ./**/*.md inputs, the folder functionality as is now, is just added, and does not replace or interrupt the old approach.