* 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

* optimize pphuman action document

* add en doc

* add break in counting for pphuman

* fix break in doc and codes

* fix mot break in region, test=document_fix

* fix region_polygon and region_type, test=document_fix

* add tools for get_video_info, test=document_fix

* update attr docs

* update more

* update docs

* 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

* attribute docs update

* fix mtmct

* update docs

* add pphuman mot doc, test=document_fix

* add mot data tutorials, test=document_fix

* Update action.md

delete the step of change model name of fight recognition

* Update video_action_infer.py

get model path from model_dir without model name

* optimize action vis

* add docs, still in working

* add action doc

* add action en doc