title: Add Qt private headers to CMake project
body: <p>How should I add Qt private headers to my CMakeLists.txt ?</p>
  <pre><code>find_package(QT NAMES Qt6 Qt5 COMPONENTS Core Quick QuickPrivate REQUIRED)
  find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Core Quick QuickPrivate REQUIRED)
  </code></pre>