* update ppvehicle modelzoo; test=document_fix

* update pipeline pictures

* update

* fix platerec jetson trtfp16; test=document_fix

* replace all --model_dir in pipeline docs; test=document_fix

* ppvehicle tutorials template

* rename pphuman docs

* update quickstart

* update ppdet docs & remove static code, test=document_fix

* add pphuman doc, test=document_fix

* update action doc, test=document_fix

* update activity, test=document_fix

* given inference model path, download model automatically

* encapsulate auto download model as a function

* given note that default model dir is download link

* change attr model download path to https://bj.bcebos.com/v1/paddledet/models/pipeline/PPLCNet_x1_0_person_attribute_945_infer.zip

* fix pphuman cfg doc, test=document_fix

* fix doc, test=document_fix

* remove en readme doc, test=document_fix

* refactor doc, test=document_fix

* update yolox & yolov5, test=document_fix

* Update README_cn.md

* update doc, test=document_fix

* Update readme and pphuman readme

* Update README.md

* add data & customize, test=document_fix

* update readme

* Update README_cn.md

* Update README_cn.md

* add template, test=document_fix
Co-authored-by: NYixinKristy <576550767@qq.com>

test=document_fix