Advanced Controls Simulations - Wording Cleanup

[gerth2]

Once https://github.com/wpilibsuite/frc-docs/pull/1821 is merged...

• Audit for all usage of vocab words and either (a) define them in the glossary or (b) substitute with a practical, FRC example.
• Audit for sections/notes which are not immediately critical for understanding sim behavior, and relegate them to hidden sections or footnotes. The goal is to make sure the learning flow is minimally interrupted.
• Audit for copy/paste repeated sections. Collect these into a common area to prevent duplication, and reference them with links