amend! devel/py-pytest-markdown: New port

devel/py-pytest-markdown: New port

You have written a README.md. In contains some of your best words. They are in
an order, and you are happy its a good order. But all those code blocks... Do
they contain valid python? This plugin will find tests in your markdown files
and run them.

Required as part of the TEST_DEPENDS heirarchy for
sysutils/py-ansible-compat

PR: 263033