Ensure examples in linter docs

[MichaelChirico]

Thanks @IndrajeetPatil for catching the mistake of sample_int_linter() lacking examples. I added those, and looked for other doc pages lacking @examples -- a few more slipped through as well.

Therefore I added a regression test to guard against this going forward.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (5674008) 99.64% compared to head (29f8ce2) 99.64%.
Report is 2 commits behind head on main.

❗ Current head 29f8ce2 differs from pull request most recent head 01a38e0. Consider uploading reports for the commit 01a38e0 to get more accurate results

Additional details and impacted files

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  Coverage   99.64%   99.64%           
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  Files         115      115           
  Lines        5290     5290           
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  Hits         5271     5271           
  Misses         19       19           

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[IndrajeetPatil]

Sorry, again, for reviewing after the PR has already been merged, but I can't do any open-source during work hours.

Thanks for adding the examples and the tests!

One thing I noticed is that we are not following the pattern we were following in all existing examples:

# will produce lints
example_with_lints

# okay
the_same_example_without_lints

The examples here don't have the same one-to-one correspondence between with and without lint code examples.