Add Default Doxygen Theme

[kilo52]

For C and C++ projects in project-init, the generated Doxygen documentation resources use the default theme provided by Doxygen itself. This works well but usually real projects end up using the doxygen-awesome theme as it tends to look nicer. Add the necessary project control code to add default support for the doxygen-awesome theme, so that it works out of the box when generating new projects.