docs(api): edit Thermocycler docstring notes

[ecormany]

Overview

I recently noticed that there was a syntax error that was hiding some notes in the docstrings for Thermocycler methods. I fixed the syntax in another PR and they became visible. But then I didn't like them! So this PR fixes them up.

Test Plan and Hands on Testing

Sandbox

Changelog

• Remove note about specifying time for profile steps. Covered by parameter entry.
• Transform note about run log behavior into a version changed statement.

Review requests

gtg?

Risk assessment

v low, docstrings

[sfoster1]

Thank you!