Before a mummified artifact is generated, it needs to have its links and other references retargeted to the target tree.
For example, a source reference to foo.xhtml or foo.md in the source tree needs to be changed to foo.html to reflect the artifact name in the target tree.
The types of links that need to be retargeted, showing the elements and corresponding attributes:
See also Is an empty href valid?.
This ticket will leave srcset to be implemented in GUISE-39, and <base> to be addressed in GUISE-40.