message: tweak CMake find_package() documentation heading
diff: @@ -159,8 +159,8 @@ example applications use
  cmake --build . --config Release --target ospray -- /m
  -Finding OSPRay with CMake
  -=========================
  +Finding an OSPRay install with CMake
  +====================================
  Client applications using OSPRay can find it with CMake's
  `find_package()` command. For example,
  