Resolution for #112 and #830

[jlarson4]

Description

• Add a logit utility that nicely displays logit vectors as requested in Add a helper function to display vectors of logits nicely #112
• Added typing from [Proposal] Type hint support for self.model in ActivationCache #830
• Broke out HookedRootModule based on Bryce's direction on [Proposal] Type hint support for self.model in ActivationCache #830

Fixes #112, #830

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have not rewritten tests relating to key interfaces which would affect backward compatibility