I agree with sitkack. npm (packaged software) is really handle to bundle code and keep a repo up to date. But I guess if you just want a markdown editor on a page, this is fine.
If you need to use npm in the rest of the project, which can be helpful for any project that uses front end Javascript, having one library (essentially) that uses a different mechanism is not great.
I have built many projects and while I swore at convoluted bundlers in the past, they are pretty nice these days.