docs: Add dots at the end of sentences

[alexandear]

This PR enables godot linter to ensure comments always end with a full stop. This is for consistency with other comments and to comply with the guidelines at https://go.dev/wiki/CodeReviewComments#comment-sentences:

Comments should begin with the name of the thing being described and end in a period

[gmlewis]

Thank you, @alexandear !
LGTM.
Merging.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.29%. Comparing base (2b8c7fa) to head (b86b2ab).
Report is 148 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3325      +/-   ##
==========================================
- Coverage   97.72%   93.29%   -4.43%     
==========================================
  Files         153      171      +18     
  Lines       13390    11729    -1661     
==========================================
- Hits        13085    10943    -2142     
- Misses        215      692     +477     
- Partials       90       94       +4     

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