On some systems pip and setuptools are no longer installed as dependencies of the python packages. This commit adds the requirement for these packages.
1. "install required python packages" in docs/zh_CN/get-started/index.rst 2. docs/zh_CN/get-started/linux-setup-scratch.rst 3. docs/zh_CN/get-started/linux-setup.rst 4. docs/zh_CN/get-started/macos-setup-scratch.rst 5. docs/zh_CN/get-started/macos-setup.rst