* Update README.md

* Update README.md

test=develop

* fix bug: use_gpu false

* fix bug: use_gpu false

* fix gpu num check bug

* fix face_detection grammatical errors (#4405)
Co-authored-by: NGuanghua Yu <742925032@qq.com>

* delete contrib Research and legacy

* add acl2019-arnor

* add readme.md for PaddleKG

* update CoKE

* fix bug of annotation file root

* fix bug of feature file not exists

2. Fix the leaving gen_data.sh in dygraph Transformer.

* fix distribute local_cluster.sh

* Update README.md (#4267)

* test=develop (#4269)

* 3d use new api (#4275)

* PointNet++ and PointRCNN use new API

* Update Readme of Dygraph BERT (#4277)

Fix some typos.

* Update run_classifier_multi_gpu.sh (#4279)

remove the CUDA_VISIBLE_DEVICES

* Update README.md (#4280)

* add similarity_net dygraph

* fix similarity_net dygraph

* fix bugs of dygraph/similarity_net

* Fix some bugs running on the GPU of dygraph/similarity_net

* fix a bug in pointwise mode of dygraph/similarity_net

* fix a bug of paddleNLP/similarity_net

* fix a bug and remove unuse files of dygraph/similarity_net
Co-authored-by: Npkpk <xiyzhouang@gmail.com>
Co-authored-by: NKaipeng Deng <dengkaipeng@baidu.com>

* Rename folder name in PaddleCV
* rename PaddleVideo to video
* rename PaddleGAN to gan
* rename Paddle3D to 3d_vision
* remove PaddleSlim

* Add PaddleDetection/release/0.2 as submodule

* Update link in models/README.md and models/PaddleCV/README.md