docs: Add instruction when to use hyphens or underscores for file and folder names under FAQ

[bobleesj]

Closes #329

Please check the rendered HTML screenshot below.

[bobleesj]

@sbillinge ready for review

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.63%. Comparing base (482eb41) to head (3d3ca24).
Report is 6 commits behind head on 202504-doc-command.

Additional details and impacted files

@@                 Coverage Diff                 @@
##           202504-doc-command     #330   +/-   ##
===================================================
  Coverage               52.63%   52.63%           
===================================================
  Files                       2        2           
  Lines                      19       19           
===================================================
  Hits                       10       10           
  Misses                      9        9           

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[sbillinge]

very nice!!!!!

[TingwenZhang]

@bobleesj @sbillinge
I noticed in https://github.com/scikit-package/scikit-package/tree/main/.codespell and https://github.com/scikit-package/scikit-package/tree/main/.github, and many other files under their subdirectories, we use _ for .txt , .md and .rst. Is this intended? Because the same is for all .codespell and .github folders under diffpy.

[bobleesj]

@TingwenZhang Great question. Thanks for asking. For the hidden files/folders, these are typically non-public facing and the naming convention is not chosen by us but by the developers of those applications. So it is important to follow their standard in order to config their apps. So, you can ignore the files under .codespell and .github.

But I will make it clearer in the documentation.

[sbillinge]

Thanks @bobleesj and @TingwenZhang great discussion.