Dynamically populate previous versions menu in the Doxygen HTML pages

[jhlegarreta]

Description

The Doxygen documentation corresponding to the previous ITK releases should be accessible through a dynamically populated menu in the HTML pages.

Expected information

Existing previous releases are dynamically loaded in the HTML page.

Actual information

Existing previous releases are hard-coded in the HTML page.

Versions

master.

Additional Information

See #3804 (comment).

[dzenanz]

This might be more trouble than it is worth. Automating this is not trivial, and the list is 5-10 items long. Manual update is probably fine. We should put it to release checklist.

[jhlegarreta]

Automating this is not trivial, and the list is 5-10 items long.

I did no mean that this should be easy/I ignore how difficult it is. It may not be an issue for a few versions, but it will be an issue at some point in time.

Excerpt from a discourse admin thread:

A follow-up on this. Related topic in the VTK discourse saying that the VTK do also have the same issue:
https://discourse.vtk.org/t/about-missing-vtk-doxygen-documentation/9926

and that ParaView folks have found a way to have the documentation of different versions available:
https://kitware.github.io/paraview-docs/latest/cxx/

[blowekamp]

This might be more trouble than it is worth. Automating this is not trivial, and the list is 5-10 items long. Manual update is probably fine. We should put it to release checklist.

IMHO the bigger reason to dynamically update the versions in the footer from all Doxygen from a single file, is to automatically update the old versions to have links to the newest versions.

[jhlegarreta]

Matt has done a beautiful job leveraging the ReadTheDocs infrastructure to host ITK's Doxygen documentation in InsightSoftwareConsortium/ITKDoxygen#17, and this issue has been addressed within the scope of that effor. Thanks @thewtex ❤️.