Edit this page link for standards broken in planemo docs

1. Goto http://planemo.readthedocs.io/en/latest/standards/docs/best_practices.html
2. Click the link "Edit on GitHub"
3. Goes to https://github.com/galaxyproject/planemo/blob/master/docs/standards/docs/best_practices.rst
3. Observe Error 404 page.

This is included from https://github.com/galaxy-iuc/standards/blob/master/docs/best_practices.rst in the planemo git repository, but that does not get handled automatically by GitHub.

Likely the "Edit on GitHub" definition needs to be special cased for everything under ``docs/standards/``

Start by locating the Edit on GitHub definition used for docs/standards/ and compare it with docs/standards/docs/best_practices.rst, which is included from galaxy-iuc/standards. Verify the generated link for best_practices.html points to the source in galaxy-iuc/standards and no longer returns a 404.

Written by the indexing model from the issue text.