[Doc] Update Readme (PaddlePaddle#1000)

* Fix links in readme

* Fix links in readme

* Update PPOCRv2/v3 examples

* Update auto compression configs

* Add neww quantization  support for paddleclas model

* Update quantized Yolov6s model download link

* Improve PPOCR comments

* Add English doc for quantization

* Fix PPOCR rec model bug

* Add  new paddleseg quantization support

* Add  new paddleseg quantization support

* Add  new paddleseg quantization support

* Add  new paddleseg quantization support

* Add Ascend model list

* Add ascend model list

* Add ascend model list

* Add ascend model list

* Add ascend model list

* Add ascend model list

* Add ascend model list

* Update README_CN.md

Co-authored-by: leiqing <[email protected]>