Suggestions to Enhance the Setup Experience

[Painthingy]

Thank you for the excellent work on this template! I have a couple of suggestions that I believe will enhance the setup experience for other users:

1. README Update for C++20 Support:
   Update the README to tell how to use C++20 instead of C++17. Specifically, the CMakeLists.txt file should be updated from:

   target_compile_features( ${PROJECT_NAME} 
       PRIVATE
           cxx_std_17
   )

   to:

   target_compile_features( ${PROJECT_NAME}
       PRIVATE
           cxx_std_20 
   )

2. .gitignore Update:
   To prevent the repository from growing unnecessarily large, it would be helpful to add the following lines to the .gitignore file to exclude local build output and IDE-specific files:

   /out/*
   /.vs/*