* update .gitignore
* Added checking for cmake include dir
* fixed missing trt_backend option bug when init from trt
* remove un-need data layout and add pre-check for dtype
* changed RGB2BRG to BGR2RGB in ppcls model
* add model_zoo yolov6 c++/python demo
* fixed CMakeLists.txt typos
* update yolov6 cpp/README.md