feat: Clarify utilies in API

[sethaxen]

Description

While the API docs have included a section for utilities, it has not appeared in the menu bar on the side. Now it does. Also, the utilities are now marked as public on Julia >= v1.11. When we deprecated pointwise_loglikelihoods, we accidentally started exporting it, and this PR now fixes this (non-breaking since we never documented it as exported).

Checklist

• PR follows official PR format
• Code style is correct (formatted using JuliaFormatter with BlueStyle).
• The new feature is listed in the Features section of the changelog if the change is non-breaking or the BREAKING CHANGES section if it is breaking.
• The patch version number been incremented if the change is non-breaking or the minor version number been incremented if the change is breaking.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.04%. Comparing base (b0ef2f9) to head (a792c7e).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #90   +/-   ##
=======================================
  Coverage   97.04%   97.04%           
=======================================
  Files          16       16           
  Lines         845      845           
=======================================
  Hits          820      820           
  Misses         25       25           

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