textproc/py-mkdocs-include-markdown-plugin: New Port

[agh_riseup.net]

Summary

Mkdocs Markdown includer plugin, provides two directives enabling users
to include Markdown, or other files into their documentation. Included
files can be either URLs, local files, or Bash wildcard globs.

https://github.com/mondeja/mkdocs-include-markdown-plugin

[agh_riseup.net]

Fix Port tests component