Set up docs with Doxygen on Azure DevOps and GitLab Pages

Since Doxygen can generate HTML doc pages from C# source, we need to automate it to build docs on Azure DevOps and push them to GitLab Pages, on each commit.

Providing access to versioned docs would be cherry on cake...

Edited Apr 10, 2019 by Martin Finkel

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information