pytorch contributing compilation

1. refer to this page to learn about the entire docs about contributing
   https://github.com/pytorch/pytorch/wiki/The-Ultimate-Guide-to-PyTorch-Contributions ： Setup the developer environment

2. need to pay attention

• setup the git proxy and enable local machine proxy only, rather use proxy in router
• check out the environment for compilation before run python3 setup.py develop https://github.com/pytorch/pytorch/wiki/Development-Tips
• when python3 setup.py develop results in submodule clone failed, caused by a network problem, refer to: https://github.com/pytorch/pytorch/wiki/Debugging-PyTorch-Build, clean the build cache and history files.

rm -rf build
git submodule deinit -f .
git clean -xdf
python setup.py clean
git submodule update --init --recursive # very important to sync the submodules
python setup.py develop                 # then try running the command again

• watch out for .bashrc's environments, which will inherited by compilation script setup.py. those environments may cause compiling failed.
  for example, i encountered the issue of cmake_find_compiler cmake unknown commands，refer to：https://discuss.pytorch.org/t/can-not-build-pytorch-eiether-in-ubuntu-or-centos/147057/11?u=tk0320

3. contributing reference table of contents
   https://github.com/pytorch/pytorch/blob/main/CONTRIBUTING.md