Potential network environment issues during usage

[linqinluli]

Provide a script to test the network environment and provide some hints to solve it. Here are the existing blocking points:

1. UV installation: cannot access github. install uv with pip instead of curl and set the pypi source. pip config set global.index-url https://mirrors.aliyun.com/pypi/simple/
2. Start python env with uv: cannot access github. modify the python standalone build source (link). Here is an example: uv python install 3.12 --mirror https://python-standalone.org/mirror/astral-sh/python-build-standalone. We can also modify the env variable: UV_PYTHON_INSTALL_MIRROR
   I'm not sure whether it's a reliable python source.
3. uv sync: cannot access pypi. set the pypi source. export UV_INDEX=https://mirrors.aliyun.com/pypi/simple/
4. Start TuFT: cannot access huggingface. set the the huggingface index. export HF_ENDPOINT=https://hf-mirror.com