docs: correct the TerminalSteps agent count

[shabeeth2]

Proposed change(s)

Clarify that len(TerminalSteps) counts agents whose episodes ended since the last env.step(), including interruptions. This matches the class documentation and agent_id length implementation.

Source: TerminalSteps implementation.

Validation

Compared the sentence with the linked TerminalSteps implementation. Markdown preview and git diff --check passed.

Checklist

• Documentation update.

[CLAassistant]

All committers have signed the CLA.

[montplaisir]

Thank you for making the documentation better! Please also fix line 95.

[shabeeth2]

Made changes to 95th line

[shabeeth2]

Fixed

[montplaisir]

👍