docs: Fix typos in optimization examples

[sjdemartini]

Description

Happened to notice what seemed to be typos in the docs around the optimizer plugin, so fixed them here.

I haven't yet used strawberry, but thanks for building this great django extension and documenting it well!

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Documentation

Issues Fixed or Closed by This PR

n/a

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[bellini666]

LGTM. Ty! :)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (fd2422d) 87.04% compared to head (e6b458d) 87.04%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #406   +/-   ##
=======================================
  Coverage   87.04%   87.04%           
=======================================
  Files          36       36           
  Lines        3056     3056           
=======================================
  Hits         2660     2660           
  Misses        396      396           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.