Lessons Learnt

This now builds thanks to the help from a Slack user by the name of Rommudoh.

Lessons learnt:

• Cmakes find_package( Boost REQUIRED) needs to have the specific components that I need in the code.
• In the top level CMakeLists.txt I needed to add target_include_directories
• In the top lelvel CMakeLists.txt I needed to add the library that I need to connect to in the target_link_libraries
• Instead of using add_executable() in the sub directory, I should have used add_library