Using original order will cause weird exception, like "RuntimeError..

* Update PicoDet adn GFl

* add changelog

* add faq

* Update README_cn.md

* Update FAQ-README.md

* Update FAQ第一期.md

* Rename FAQ-README.md to README.md

* Update README_cn.md

* Update FAQ第一期.md

* delete 2 files

* Delete .DS_Store

* fix use_gpu in deploy doc,  test=document_fix

* fix deploy doc, test=document_fix

* add gfl model and PicoDet

* add kitti metric

* clean kitti metric code

* fix kitticars doc

* remove kitti headtracking cfgs

* remove kitti headtracking cfgs, clean code

* fix datatype and ffmpeg, test=document_fix

* add soft link, test=document_fix

* add doc link, test=document_fix

* fix deploy image_list, test=document_fix

* add the config of fairmot_headtracking

* add flops

Besides removing unnecessary imports, this also fixes the missing logger module in test_architectures.py within the static directory.

* fix_install_docs

* fix_install_docs2

* add document for keypoint dataset preparation

* test=document_fix

* test=document_fix

* 关键点文档中json示例格式化显示，test=document_fix

* add doc

* add FAQ

* update 2.1 readme

* update en doc, test=document_fix

* update doc, test=document_fix
Co-authored-by: NGuanghua Yu <742925032@qq.com>

* fix jde negative coords

* update jde model zoo

* describe format for some txt, test=document_fix

* fix mot doc

* remove image_lists, fix all mot docs, add custom data

* fix doc, test=document_fix

* fix dov

* fix doc format, test=document_fix

* update install docs

* fix slim doc,test=document_fix

* add config for jde and deepsort, add engine metric tools

* add mot_metrics

* fix configs engine and others

* fix configs others

* move configs

* fix ap_per_class, fix doc

* fix test_mode, seqs

* fix test_mode to metric

* fix JDE arch metric

* clean requirement

* add to requirement

* add inference benchmark

* add mot data

* fix operators, source

* fix data source transform

* fix parse_dataset register_op

* fix scale_factor, RandomAffine

* add assert for check

* fix ci

* add lite demo