Updates for cmake and project structure

[JeffGarland]

Just taking the project for a spin there's some issues (see below). Quite likely there's a problem in exemplar and cookie cutter, but regardless will fix locally here. Also, this is header only so will eliminate the src directory complications.

cmake .. -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_CXX_STANDARD=26 -G=Ninja
CMake Error at src/beman/take_before/CMakeLists.txt:22 (find_package):
  By not providing "Findbeman-install-library.cmake" in CMAKE_MODULE_PATH
  this project has asked CMake to find a package configuration file provided
  by "beman-install-library", but CMake did not find one.

  Could not find a package configuration file provided by
  "beman-install-library" with any of the following names:

    beman-install-libraryConfig.cmake
    beman-install-library-config.cmake

  Add the installation prefix of "beman-install-library" to CMAKE_PREFIX_PATH
  or set "beman-install-library_DIR" to a directory containing one of the
  above files.  If "beman-install-library" provides a separate development
  package or SDK, be sure it has been installed.