Add examples of other CLI libraries

Imported from gh:painless-software/python-cli-test-helpers#30, gh:painless-software/python-cli-test-helpers#53, gh:painless-software/python-cli-test-helpers#60

There are more CLI modules that may be worth demonstrating in this project.

Package Description Repository Documentation
clypi Your all-in-one for beautiful, lightweight, prod-ready CLIs. gh:danimelchor/clypi danimelchor.github.io/clypi
Python Fire Automatically generate CLIs from absolutely any Python object. gh:google/python-fire google.github.io/python-fire
Rich Python library for rich text and beautiful formatting in the terminal. gh:textualize/rich rich.readthedocs.io
Typer Typer, build great CLIs. Easy to code. Based on Python type hints. gh:fastapi/typer typer.tiangolo.com

Feel free to suggest more by adding a comment! ✏️

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