Add Backend files

Backend/darknet/.circleci/config.yml

Backend/darknet/.github/FUNDING.yml

...net/.github/ISSUE_TEMPLATE/any-other-question-or-issue.md

Backend/darknet/.github/ISSUE_TEMPLATE/bug-report.md

Backend/darknet/.github/ISSUE_TEMPLATE/feature_request.md

...ng-issue---no-detections---nan-avg-loss---low-accuracy.md

Backend/darknet/.github/workflows/ccpp.yml

Backend/darknet/.gitignore

Backend/darknet/.travis.yml

Backend/darknet/3rdparty/pthreads/include/pthread.h

Backend/darknet/3rdparty/pthreads/include/sched.h

Backend/darknet/3rdparty/pthreads/include/semaphore.h

Backend/darknet/3rdparty/stb/include/stb_image.h

Backend/darknet/3rdparty/stb/include/stb_image_write.h

Backend/darknet/CMakeLists.txt

Backend/darknet/DarknetConfig.cmake.in

Backend/darknet/LICENSE

Backend/darknet/Makefile

Backend/darknet/README.md

Backend/darknet/bad.list