SFML tutorial: https://www.sfml-dev.org/tutorials/2.6/
SFML: https://github.com/SFML/SFML
json for c++: (old) https://github.com/open-source-parsers/jsoncpp
nlohmann json: (new) https://github.com/nlohmann/json
Spdlog (v1.12.0): https://github.com/gabime/spdlog/releases/tag/v1.12.0