Linked markdown files in README don't get HTMLized, so get lost in documentation

[bencresty]

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Short summary of your issue

First of all, thanks for all the hard work. The generated documentation looks great and is super useful!
I love it that README.md is converted to the 'home' page of the documentation. However, for a lot of projects the README gets overly big, so we split these into sub markdown files where the README.md is for a big part a table of contents page to all sub-pages per section. But these files give 404 errors in the final documentation because these don't get included in the documentation.

This is how a link looks like in README.md:

See [Loaders](readme-includes/usingLoaders.md)

I can't get this to work with esdoc; these sub-pages, linked in README.md, don't make it to the documentation and still link to the original markdown files instead. Those files aren't in the package so can't be found. And even if they were, browers can't interpret markdown files. So the link is there, but the page is throwing a 404, making subpages in README not an option when using esdoc unfortunately.

Is there perhaps a setting I'm missing that makes this possible? Or else, would you please consider following links to sub-markdown files from README and make html pages of these too when converting the README markdown to html?
Or if that's too complicated, perhaps a setting in the config to add a way to add extra markdown files to be converted to html (keeping the structure, so the HTMLized readme can find these 'sub'-files)

Input data for reproducing

This in README.md:

See [Loaders](readme-includes/usingLoaders.md)

Add a folder readme-includes in the root of the project and add a markdown file usingLoaders.md inside that folder.

Your environment

• OS type and version: Windows 10
• Node.js version: 14.15.3
• ESDoc version: 1.1.0