CMake: inconsistency of include interface between pkg-config and CMake config file

[SpaceIm]

In CMakeLists, include interface is defined under include (for CMake config file in install target):

rtmidi/CMakeLists.txt

Line 197 in e8ae727

$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)

but headers are installed under include/rtmidi:

rtmidi/CMakeLists.txt

Line 248 in e8ae727

PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/rtmidi)

In the meantime, .pc file says that include interface is under include/rtmidi:

rtmidi/rtmidi.pc.in

Line 4 in e8ae727

includedir=${prefix}/include/rtmidi

It's inconsistent.
Someone consuming rtmidi with CMake config files must include public header with #include <rtmidi/RtMidi.h>, but with pkg-config it won't work and it will be #include <RtMidi.h>.
With add_subdirectory(), it is also #include <RtMidi.h>

Moreover, in all samples and tutorials, it's #include <RtMidi.h>