[pip] doc

https://pip.pypa.io/en/stable/

https://pip.pypa.io/en/stable/user_guide/#

https://pip.pypa.io/en/stable/cli/

The general options that apply to all the commands listed below can be found under thepippage in this section.
ENVIRONMENT MANAGEMENT AND INTROSPECTION

• pip install
• pip uninstall
• pip list
• pip show
• pip freeze
• pip check

HANDLING DISTRIBUTION FILES

• pip download
• pip wheel
• pip hash

PACKAGE INDEX INFORMATION

• pip search

MANAGING PIP ITSELF

• pip cache
• pip config
• pip debug