Cannot use with C++20 modules

[kridenberg]

I try to use mrdocs under Windows (CMake with Ninja generator and CLang 21), with a code base that consists mostly of C++20 modules. We use the .ixx file extension to mark primary interface units and partitions, and .cxx to identify module implementation units. I do not know if that is a lack of module support by the mrdocs (I cannot find explicit statements about that), or a lack of the .ixx extension support (I tried to explicitly add the .ixx extension with file-patterns), but I receive a bunch of the "Skipping non-C++ file: /.ixx" errors.