add model path searcher and remove hardwritten file paths from benchmark configs; pack ppresnet, mobilenet & crnn with labels; fix palm det data; add flags to enable models of different precision separately (#123)

Signed-off-by: NHelio Perroni Filho <xperroni@gmail.com>
Signed-off-by: NHelio Perroni Filho <xperroni@gmail.com>

* Fix a bug when there is no object

* Add the minimum version requirement for opencv-python

* re-quantize some models from per_channel mode to per_tensor mode

* remove the description about per_channel

Delete YoloX.py (#111):

- Remove the legacy to save git conflicts

[Fix]: Fix variable name error (#110)

Resolves #108:

- Renamed `YoloX.py` to `yolox.py` for import.

- Reimplemented batched-nms.

- Put anchor generation in the initialization stage to avoid re-generating in inference.

Improved help messages for demo programs (#95)
- Added Demo Documentation
- Updated help messages
- Changed exception link

add object detection model YoloX

add object detection model NanoDet

* add crnn int8 EN

* add crnn int8 (ch)

* revise models

* rename models

* revise the quantize-ort to quantize crnn into int8 with high accuracy

* change the comment to English

* reduce supported suffix

* add crnn CH FP16 model

* add crnn EN FP16 model

* update readme

* add another script

* revise details for this pr

* Add script to evaluate face detection by WIDERFace

* add the result of YuNet

* addDBfrontpage

* add English DB

* change readme

* change two readme and replace images

Add more demos to front page

* add demo images

* add demo to readme

* add lpd_yunet

* add quantization and quantized model

* quantize with inc instead

* update benchmark results