title: What's the use of configure_package_config_file option INSTALL_DESTINATION
body: <p>For the following <code>CMakeLists.txt</code> file</p>
  <pre><code>cmake_minimum_required(VERSION 3.15)
  project(Testing)
  
  include(CMakePackageConfigHelpers)
  configure_package_config_file(FooConfig.cmake.in
    ${CMAKE_CURRENT_BINARY_DIR}/FooConfig.cmake
    INSTALL_DESTINATION lib/Goo/dmake
  )
  
  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/FooConfig.cmake
          DESTINATION lib/Foo/cmake )
  </code></pre>
  <p>and the <code>FooConfig.cmake.in</code> file</p>
  <pre><code>@PACKAGE_INIT@
  
  check_required_components(Foo)
  </code></pre>
  <p>It would finally install <code>FooConfig.cmake</code> to <code>lib/Foo/cmake</code>：</p>
  <pre><code>$ cmake ..
  $ cmake --build .
  $ cmake --install . --prefix ../install/
  $ ls -R ../install/
  ../install/:
  lib
  
  ../install/lib:
  Foo
  
  ../install/lib/Foo:
  cmake
  
  ../install/lib/Foo/cmake:
  FooConfig.cmake
  </code></pre>
  <p>It seems that whatever value I set to the <code>INSTALL_DESTINATION</code> option of <code>configure_package_config_file</code>, it won't change <code>FooConfig.cmake</code>'s installation directory. But if I comment <code>INSTALL_DESTINATION lib/Goo/dmake</code>, CMake Error prompts</p>
  <blockquote>
  <p>No INSTALL_DESTINATION given to CONFIGURE_PACKAGE_CONFIG_FILE()</p>
  </blockquote>
  <p>Then, what is the use of the <code>INSTALL_DESINATION</code> option? What its value (specifically, the above setting <code>lib/Goo/dmake</code>) actually affects?</p>
  <hr />
  <p>The <a href="https://cmake.org/cmake/help/v3.22/module/CMakePackageConfigHelpers.html#command:configure_package_config_file" rel="nofollow noreferrer">documentation</a>:</p>
  <blockquote>
  <p>The <code>&lt;path&gt;</code> given to <code>INSTALL_DESTINATION</code> must be the destination where the <code>FooConfig.cmake</code> file will be installed to.</p>
  </blockquote>
  <p>I know the right way is <code>INSTALL_DESTINATION lib/Foo/cmake</code>. But as I deliberately set it as <code>lib/Goo/dmake</code>, the  <code>FooConfig.cmake</code> file still rests at the desired destination <code>lib/Foo/cmake</code>. So, why this option is designed as a must?</p>