Cleanup — README, executable permissions, import sort, pyproject.toml config

[rsnodgrass]

Description

• updated README and moved Adafruit notice to separate file (to avoid confusion and polluting the main documentation) — this should still comply with the Adafruit notice requirement as the separate file is also included in the redistribution
• added Credits section to README
• ran isort on Python code to sort imports
• add pyproject.toml where configuration options for Python tools can be set (e.g. isort/ruff/refurb/etc)
• removed executable permissions flag from files that are not executable

Related Issue

No new code. This is all documentation, project config, and Python isort run results.

Motivation and Context

Simplification.

How Has This Been Tested

No code changes (other than import sorting).

Types of changes

• [X] 🐛 Bug fix (non-breaking change which fixes an issue)
• [ ] 🚀 New feature (non-breaking change which adds functionality)
• [ ] 🌎 Translation (addition or update a translation)
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [X] My code follows the code style of this project.
• [X] My change requires a change to the documentation.
• [X] I have updated the documentation accordingly.
• [X] I have tested the change locally.

[crismc]

Thanks for the cleanup :)