Modify language regarding installing python and python package managers

[liaochris]

In this issue, we will update the language about
a) installing python
b) python package managers

to be more distribution/software agnostic.

[liaochris]

Conversation continues in #145

[github-actions]

Summary

In this issue, we changed the language around python distribution and package managers to be agnostic about software choice, but recommend a few popular tools.

Last commit in issue branch: 4c585e7
Branch merged in 320e6f4