Here are excerpts from the readme:
This gem was built specifically to empower the creation of structured legal documents using markdown, and a markdown renderer. This gem acts as a middle layer by providing the user with structured headers and mixins that will greatly empower the use of md to create and maintain structured legal documents. [...]
This gem will parse YAML Front Matter of Markdown Documents. Typically, this gem would be called with a md renderer, such as Pandoc, that would turn the md into a document such as a .pdf file or a .docx file. By combining this pre-processing with a markdown renderer, you can ensure that both the structured content and the structured styles necessary for your firm or organization are more strictly enforced. Plus you won’t have to deal with Word any longer [...]
Gitlaw is markdown agnostic at this point and needs to be called independently of any markdown renderer. It is easy enough to build it into your work flow by editing the way that your markdown renderer is called. For instance you can call this file just before pandoc builds it. [...]
For more details, please see the complete documentation.
The idea of using Markdown to edit legal documents has been raised in the context of the GitLaw discussion.