Extended syntax support

[dnswd]

A few days ago, while you're away, I tried to implement several extended markdown syntaxes while learning how to build a parser. I tried to list some of them based on markdownguide's extended syntax page and list of markdown-supported tools. I tried to do it by myself, but since I work alone and barely know how parsers work, there's not so much progress I can make. Here's my kanban list of syntaxes so far.

Since you're back, I think it's appropriate to talk with you about this first. I believe supporting extended markdown syntax is an excellent way to make a fully functional and flexible markdown parser.
I want to hear what you think about this idea.

[ubersl0th]

I've invited you as a collaborator if you want it.

As for extended syntax support, I think it would be great to support it, however I don't have deep knowledge about the source code or markdown parsers. As stated in this repo description, this is a fork of another project ported to work for the Deno runtime. I have not written this code.

But feel free to experiment with additional features and improvements as much as you like 👍

[dnswd]

however I don't have deep knowledge about the source code or markdown parsers.

In that case, you might want to add a contributing guide to explain some basics of the project, such as entry file and general workflow. Just in case someone more knowledgeable wants to contribute.

Also, consider adding a licence.

[dnswd]

@ubersl0th I created a kanban board for the extended syntax to see the progress. I'm also making a contributing guide, you can view the draft on contributing branch