* test=update_icons, test=release/2.3

* test=update_icons, test=release/2.3

* Update PP backbones‘ introduction

Update PP backbones‘ introduction

* Update sample image link

Update sample image link

* delete paddlecv whl package

delete paddlecv whl package

* Add model icons of OCR and Class

Add icons of OCR and Class

* update paddleclas to 2.5.1 in requirements.txt and add an .ttf font file

* update requirements.txt

* update introduction

* update introduction

* update paddleclas to 2.5.1 in requirements.txt and add an .ttf font file

* update requirements.txt

* update PP-ShiTuV2 files

* update PP-ShiTu

* add PP-ShiTuV2 APP files

* refine code

* remove PP-ShiTuV1' APP

* correct  in info.yaml

* update partial en docs

* update

* Update info.yaml

* Update info.yaml
Co-authored-by: NliuTINA0907 <65896652+liuTINA0907@users.noreply.github.com>

* test = add the PP-YOLOv2 Demo to ModerCenter

* test = update the PP-YOLOv2 Demo to ModerCenter

* test = update the PP-YOLOv2 Demo to ModerCenter

* test = add the folders for related models
Co-authored-by: NYang <yangyehua@baidu.com>