Tutorial: Make `INSTALL_DESTINATION` consistent with installed destination

Help/guide/tutorial/Step12/CMakeLists.txt

@@ -97,7 +97,7 @@ include(CMakePackageConfigHelpers)
 # generate the config file that includes the exports
 configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/Config.cmake.in
   "${CMAKE_CURRENT_BINARY_DIR}/MathFunctionsConfig.cmake"
-  INSTALL_DESTINATION "lib/cmake/example"
+  INSTALL_DESTINATION "lib/cmake/MathFunctions"
   NO_SET_AND_CHECK_MACRO
   NO_CHECK_REQUIRED_COMPONENTS_MACRO
   )