Add documentation on how to enable compilation of binary dependencies.

[dwt]

This feels more complicated than it should be. Especially setting the export DYLD_FALLBACK_LIBRARY_PATH="${rosettaPkgs.lib.makeLibraryPath [ rosettaPkgs.gcc14.cc] }:$DYLD_FALLBACK_LIBRARY_PATH" feels like it should just go into either languages.python.libraries or into packages. I didn't get that to work however.

This would fix #1603