[Docs] Add venv instructions and remove community packages

[waffle87]

Description

Adds virtual environment instructions for PEP668 victims and removes mentions of Arch Linux community packages, as they are generally more broken than functional.

Types of Changes

• Documentation

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).