message: Added target_include_directories() to properly export include directories
  Fixes
diff: @@ -55,6 +55,10 @@ if(BUILD_PKGCONFIG)
  set(INSTALL_SUFFIX /pugixml-${PUGIXML_VERSION_STRING})
  endif()
  +target_include_directories(pugixml PUBLIC
  + $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/src>
  + $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}${INSTALL_SUFFIX}>)
  +
  install(TARGETS pugixml EXPORT pugixml-config
  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}${INSTALL_SUFFIX}
  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}${INSTALL_SUFFIX}
  