ModelInstances and Tests were left out of the generated documentation, which was a mistake.
LaTeX generation failed; even if LaTeX document is not very wieldy this highlights problems in my use of Doxygen (for instance putting code within a parameter doesn't give a good rendering either in html format).
Add a link to README.md for the main page
Provide three levels of documentation (basic, advanced, internal)
There was also the issue that output directory was related to my own account.