better installation instructions on windows

[phineas-pta]

just stumble upon your repo when trying to use real-esrgan with tensorrt, i think the instructions can be a bit better, especially windows and the .bat file

nvidia docs are very long and complicated, i write my own guide to install CUDA + cuDNN + TensorRT on windows: https://github.com/phineas-pta/NVIDIA-win/blob/main/NVIDIA-win.md (u can use this to make tutorial video if u want)

for python packages here my suggestions:

1. install torch if cuda 11.8: pip install torch torchvision --index-url https://download.pytorch.org/whl/cu118 if cuda 12.1: pip install torch torchvision --index-url https://download.pytorch.org/whl/cu121

2. install tensorrt if linux: pip install tensorrt if windows: pip install + the tensorrt .whl file in the folder downloaded when install TensorRT no need to install onnx_graphsurgeon nor tensorrt_dispatch nor tensorrt_lean also seem like in the future (not now) with tensorrt v9 u can do pip install tensorrt on windows

3. install packaging with pip install packaging

4. install torch2trt with pip install git+https://github.com/NVIDIA-AI-IOT/torch2trt.git no need to git clone