State in the execute_process how COMMAND arguments are passed to the child. Add a note at the end about how the command differs from add_custom_*(). Suggested-by: Alan W. Irwin
Use a code-block for the signature. Format the options as a definition list.
Run the convert-help.bash script to convert documentation: ./convert-help.bash "/path/to/CMake-build/bin" Then remove it.
Brad King
Kitware Robot