Preferred integration of this library

[awvwgk]

Thanks for the nice work with this library.

I'm currently trying to bridge a library of mine with date time serialization / deserialization support to other date time libraries (see https://github.com/toml-f/toml-f/pull/103). For two other date time libraries (https://github.com/wavebitscientific/datetime-fortran and https://github.com/urbanjost/M_time) this was quite easy to realize due to support for the Fortran package manager (https://fpm.fortran-lang.org).

I would like to include a section on this library as well, however the overhead from describing a robust CMake integration is quite substantial (see https://toml-f.readthedocs.io/en/latest/how-to/integration/#integrate-with-cmake for an example), having support for fpm as well would make this library more accessible for users.

If there is interest I can provide a patch for enabling fpm support in this project as well.