This system adds support for Markdown syntax in both documents and docstrings. When this system is loaded, Staple will automatically scan for documents with the ending md to use as primary documents on inferred pages. It also adds the source-compiler :markdown that can be used to markup documentation source.
To use Markdown for docstrings as well, use a customisation like this on your page type:
(defmethod staple:format-documentation ((docstring string) (page my-page))
(let ((*package* (first (staple:packages page))))
(staple:markup-code-snippets-ignoring-errors
(staple:compile-source docstring :markdown))))