Now the configs follows the standard cmake-package code: see https://cmake.org/cmake/help/v3.12/manual/cmake-packages.7.html
Downstreamer no longer have to manually specify target_include_directories with ${ASSIMP_INCLUDE_DIRS}, target_link_libraries with ${ASSIMP_LIBRARY_DIRS} and so on.
Downstreamer can now use:
find_package(assimp CONFIG REQUIRED)
target_link_libraries(AWESOME_APP PUBLIC assimp::assimp)
and everything should work.
Added assimpTargets.cmake.in
Added assimpTargets-debug.cmake.in
Added assimpTargets-release.cmake.in
Modified CMakeLists.txt
Modified code/CMakeLists.txt - added ALIAS assimp::assimp
Tested on Ubuntu 18.04 and Windows 10