IO Pages links to fehmpytests not working

[millerta]

Links from github IO pages are not working for files under fehmpytests/ testname/_information
We would like the test description files to link to images and documents in the test sub directories.
But the display for these links is inconsistent.
Use fehmpytests darcy2D as an example that needs fixing.

See markdown page at
FEHM/docs/getting-started/fehmpytest-info/test-details/darcy2D.md

This link works:
Documents and Image Directory: [FEHM/fehmpytests/darcy2D/_information](https://github.com/lanl/FEHM/tree/master/fehmpytests/darcy2D/_information)


This link does not display under markdown, but does display as github pages:
<a href="../../../../img/contour_darcy_m9_m6.png"> <img width="400" src="../../../../img/contour_darcy_m9_m6.png"> </a> 

This link does display under markdown, but does not display as github pages:
 <a href="https://github.com/lanl/FEHM/blob/master/fehmpytests/darcy2D/_information/contour_darcy_m9_m10.png"> <img width="400" src="https://github.com/lanl/FEHM/blob/master/fehmpytests/darcy2D/_information/contour_darcy_m9_m10.png"> </a>