Added Doxygen structure for C++ files

[jbrzensk]

I added basic headers for all files and basic oxygen structure for the mimetic operators.
Some of the code is self-explanatory and does not need explanation ( like operators.h).

Some comments, like the interpolators, need more explanation, like why/when the second-type interpolators are used.

This is a good starting block for future Doxygen edits.

[valeriabarra]

Thanks @jbrzensk !

Hey @pritkc , do you mind checking out this branch DOCUMENTATION_doxygen_for_cpp and testing the Doxygen changes that Jared is introduing? Let us know if you have specific comments/questions in the PR Review tab.

Thank you!

[pritkc]

Thanks @jbrzensk !

Hey @pritkc , do you mind checking out this branch DOCUMENTATION_doxygen_for_cpp and testing the Doxygen changes that Jared is introduing? Let us know if you have specific comments/questions in the PR Review tab.

Thank you!

I've added it to my list, thanks

[valeriabarra]

Thank you @jbrzensk for your work! I was able to test locally and visualize the generated html files. Nice job!