typo fix in pesq docs

[ivnvalex]

What does this PR do?

Fixes #1446

Before submitting

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

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[codecov]

Codecov Report

Merging #1447 (1f289e7) into master (ef8fcb1) will decrease coverage by 55%.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1447     +/-   ##
========================================
- Coverage      90%     35%    -55%     
========================================
  Files         211     211             
  Lines       10850   10850             
========================================
- Hits         9720    3755   -5965     
- Misses       1130    7095   +5965