Headers are not supposed to get bundled into a library binary. A dylib is a shared library that is binary only.
A dylib is not the same thing as a framework (which is a bundle of a library and its headers) - I guess that is where your confusion comes from.
For allowing you to include the headers needed for using functions of your library, you will need to put those into the header-search-path of your compiler. You may certainly also extend that path towards any folder that contains your header/s.
Since you are using some packaging script as it seems, check with the documentation of that script (or simply analyse it).
And as a final note, do not use the sharp brackets (<, >) for delimiting custom header includes. Only system headers are supposed to get those. Use standard quote marks instead (").