fix: add proposed pipeline for producing md

[BelfordZ]

Note: this is moslty throwaway, and is just here to demonstrate a particular pattern for generating the markdown.

The positives of this approach:

• its all just typescript code, and testing components of it thoroughly should be easier
• the use of unified lets us easily generate other types of content, not just markdown
• the intermediate representation of the document can be manipulated as part of plugin scheme for adding extensions
• since it does not use templates, we dont have the problem of poor text editor support for template files / programs inside templates are generally hard to unit test

Negatives:

• somewhat heavy use of libs, not even dev deps either. we could follow the pattern and hand roll the typings we need... but that will certainly add more scope.
• doesn't appeal to the designer who wants to write the markdown and then apply the template vars later. The process becomes somewhat backwards where you need to render the markdown, view in a markdown viewer, determine the changes you want to make, then translate those changes into the code.