* 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

* test=documents_fix,test=release/2.3

* test=documents_fix,test=release/2.3

* add install of paddleclas

* update inference with paddlecv

* change cv to Computer Vision

* update info.yml

* Update info.yaml

* Update info.yaml

* Update info.yaml

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

* add install of paddleclas

* update inference with paddlecv

* change cv to Computer Vision

* add PP-OCRv2

* add PP-OCRv2 benckmark

* update app

* update introduction

* update PP-OCRv2 introduction

* add pipeline of PP-OCRv2

* add PP-OCRv3

* update benckmark

* add paddleocr to requirements

* update

* support paddleocr 2.6.0.1

* rm print code

* add image download

* add model train

* update PP-OCRv3 ref

* update doc

* update doc

* update PP-OCR info

* add PP-StructureV2

* update doc

* merge upstream

* update info.yaml

* add PP-OCRv2

* add PP-OCRv2 benckmark

* update app

* update introduction

* update PP-OCRv2 introduction

* add pipeline of PP-OCRv2

* add PP-OCRv3

* update benckmark