wrong include of nlohmann's json.hpp

[msva]

Hi there!
I found that main.h states inclusion of nlohmann's json parser as just #include <json.hpp>, but not as #include <nlohmann/json.hpp>, which is recommended in it's README: https://github.com/nlohmann/json#integration. By default, it installs the header to /usr/include/nlohmann/json.hpp, and not in /usr/include/json.hpp. And neither it's cmake files declares /usr/include/nlohmann as default search path for the header.

So, despite of your call to find_package(nlohmann_json), /usr/include/nlohmann is still not included in default headers search path.
So, it leads to build failure because compiler can't find json.hpp.