Help/guide: fix importing-exporting CMake install destinations

Help/guide/importing-exporting/MathFunctions/CMakeLists.txt

@@ -31,7 +31,7 @@ install(FILES MathFunctions.h DESTINATION include)
 install(EXPORT MathFunctionsTargets
         FILE MathFunctionsTargets.cmake
         NAMESPACE MathFunctions::
-        DESTINATION lib/cmake
+        DESTINATION lib/cmake/MathFunctions
 )
 
 # include CMakePackageConfigHelpers macro
@@ -58,14 +58,14 @@ write_basic_package_version_file(
 # create config file
 configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in
   "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfig.cmake"
-  INSTALL_DESTINATION lib/cmake
+  INSTALL_DESTINATION lib/cmake/MathFunctions
 )
 
 # install config files
 install(FILES
           "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfig.cmake"
           "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfigVersion.cmake"
-        DESTINATION lib/cmake
+        DESTINATION lib/cmake/MathFunctions
 )
 
 # generate the export targets for the build tree