Fix broken default installation

[lorenzomammana]

Summary

Fix quadra not installed properly without the onnx extra, minor fixes to the documentation.

Type of Change

• Bug fix (non-breaking change that solves an issue)

Checklist

Please confirm that the following tasks have been completed:

• [X] I have tested my changes locally and they work as expected. (Please describe the tests you performed.)
• [X] I have added unit tests for my changes, or updated existing tests if necessary.
• [X] I have updated the documentation, if applicable.
• [X] I have installed pre-commit and run locally for my code changes.