* update doc on develop, test=document_fix

* update dependency of ppdet and paddle, test=document_fix

* update docs, test=document_fix

* update README

* update doc, test=document_fix

* add citation

* update citation and ppyolo doc

* update readme en, test=document_fix

* update doc

* add christmas application

* fix element source

test=document_fix

* update some link in README

* fix product news

* update v0.5 release note

* update some comments

* Correct Format of README_en.md
* Update README_cn.md
* Correct details in README_en.md

* update link on README

* use relative path

* add PP-YOLO README en

* v0.4.0 change log

* add PPYOLO
Co-authored-by: Nlongxiang <longxiang@baidu.com>

Add practical generic detection models containing 676 categories

* fix voc dataset and docs

* add custom datsset demo

* fix README for yolov3

* add NOTE

* fix some docs link error

* rename config_doc

* fix export_model doc link error

* sort out release/0.3 docs

* add new CHANGELOG

* add yolov4 in changelog

* add detailed doc
* add zh_CN doc of pssdet
* fix link

* Update docs
* Update README.md

* add map_fps fig

* Organize and document mobile models

* Clean up trailing whitespaces

* Change bullet type

* Minor wording fixes

* Fix yolo naming

* Add link in repo README.md

* deploy/cpp : Update cpp ineference solution

* add README.md to deploy

* deploy/cpp : add PadStride

* deploy/cpp : add output visualization

* deploy/cpp: add video support

* fix coding style problem

* deploy/cpp : add README.md

* deploy/cpp : update docs

* deploy/cpp : update linux build scripts

* deploy/cpp : update linux build docs

* udpate docs

* deploy/cpp : update windows build docs

* depoy/cpp: fix coding style

* fix coding style

* Create CMakeSettings.json

* Update README.md

* Update windows_vs2019_build.md

* Update CMakeLists.txt

* Update linux_build.md

* Update CMakeLists.txt

* deploy/cpp : update linux build script

* update doc structures and support arch Face

* Update README.md
* Update change logs
* Update docs/advanced_tutorials/inference/INFERENCE.md

* fix all documentation

* fix docs conf.py

* fix some error

* fix readthedocs

* Add GIOU loss.
* Add DIOU/CIOU loss.
* Change loss box type in bbox_head.py.
* Remove fuse_elewise_add_act_ops flag in train.py (Error may happen for elem_divbased on the flag).

- 1.add cn docs
- 2.fix fddb evaluate
- 3.fix get_shrink
- 4.delete FLAGS.dataset_dir

* add res2net model

* modify yml files

* add res2net model zoo

* add hrnet model

* modify model zoo

* minor fix readme

* update readme in dirs

* minor fix softnms bug

* refine model zoo

* modify yml files

* modify pretrain names