02-Use_the_Tools_Available.md -> cmake/coite ist deprecated

coitre declares itself as depreacted:

from https://github.com/sakra/cotire/:

> The functionality provided by cotire has been superseded by features added to [CMake 3.16](https://cmake.org/cmake/help/latest/release/3.16.html). Support for [pre-compiling](https://cmake.org/cmake/help/latest/command/target_precompile_headers.html) and [unity builds](https://cmake.org/cmake/help/v3.16/prop_tgt/UNITY_BUILD.html) is now built into CMake. Thus, there will not be any further updates or support for this project.