Fix some typos in the gallery examples

[zm711]

Motivation

Just noticed some typos in the gallery and tried to clarify a couple things. (Also and maybe this is just me but I really prefer calling it simulated data in examples because fake data has such a negative connotation).

What was the reasoning behind this change? Please explain the changes briefly.
Fix typos. Try to clarify a couple points.
Add articles when missing. Ad ly to adverbs. Use correct modal verb. Switch a few places to a more standard US-English positioning of words. Switched fake -> simulated.

I'm happy to do some more docs read throughs, but I figured it is easier to do this in smaller batches. Let me know if you'd prefer a different format for the PRs for docs only.

How to test the behavior?

No testing. Just the written portion of the gallery docs. No changes to the functions themselves.

Checklist

• Did you update CHANGELOG.md with your changes? Do you want this for a doc change?
• Have you checked our Contributing document?
• Have you ensured the PR clearly describes the problem and the solution?
• Is your contribution compliant with our coding style? This can be checked running flake8 from the source directory.
• Have you checked to ensure that there aren't other open Pull Requests for the same change?
• Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged. NA

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (82c4f2b) 91.99% compared to head (c214f74) 83.68%.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #1825      +/-   ##
==========================================
- Coverage   91.99%   83.68%   -8.32%     
==========================================
  Files          27       27              
  Lines        2623     2623              
  Branches      685      685              
==========================================
- Hits         2413     2195     -218     
- Misses        138      344     +206     
- Partials       72       84      +12     

Flag	Coverage Δ
integration	?
unit	83.68% <ø> (ø)

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[rly]

This is great! Thank you for fixing all of these, @zm711 . I added a changelog entry to give you more visible credit for your contributions.