anchor.diff:  |CMAKE_SOURCE_DIR |The root source directory
   
   |CMAKE_CURRENT_SOURCE_DIR |The current source directory if using
  -sub-projects and directories
  +sub-projects and directories.
   
  -|PROJECT_SOURCE_DIR |The source director of the current cmake project.
  +|PROJECT_SOURCE_DIR |The source directory of the current cmake project.
   
   |CMAKE_BINARY_DIR |The root binary / build directory. This is the
  -directory you run the cmake command from
  +directory where you ran the cmake command.
   
   |CMAKE_CURRENT_BINARY_DIR |The build directory you are currently in.
   
   |PROJECT_BINARY_DIR |The build directory for the current project.
   |=======================================================================
   
  -[[including-directories]]
  -Including Directories
  -^^^^^^^^^^^^^^^^^^^^^
  +## Including Directories
   
   When you have different include folders, you can make your compiler aware of them using the
   +include_directories()+ function. This will add these directories to the
  
positive.code:     └── main.cpp
  ```
  
    * CMakeLists.txt - Contains the CMake commands you wish to run
    * inc/Hello.h - The header file to include
    * src/Hello.cpp - A source file to compile
    * src/main.cpp - The source file with main
  
  [[concepts]]
  Concepts
  ~~~~~~~~
  
  [[directory-paths]]
  Directory Paths
  ^^^^^^^^^^^^^^^
  
  CMake syntax specifies a number of https://cmake.org/Wiki/CMake_Useful_Variables[variables]
  which can be used to help find useful directories in your project or source tree.
  
negative.code:     )
  ----
  
  ## Source Files Variable
  
  Creating a variable which includes the source files allows you to be
  clearer about these files and easily add them to multiple commands, for example,
  