Fix formatting in configuration documentation

[djhoese]

Noticed some bad style related to how I put s after a double backtick.

[codecov]

Codecov Report

Merging #1950 (c77f576) into main (f901396) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1950      +/-   ##
==========================================
- Coverage   93.53%   93.53%   -0.01%     
==========================================
  Files         279      279              
  Lines       41317    41312       -5     
==========================================
- Hits        38647    38642       -5     
  Misses       2670     2670              

Flag	Coverage Δ
behaviourtests	4.77% <0.00%> (+<0.01%)	⬆️
unittests	94.07% <100.00%> (-0.01%)	⬇️

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Impacted Files	Coverage Δ
satpy/tests/writer_tests/test_awips_tiled.py	98.47% <100.00%> (-0.03%)	⬇️

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[coveralls]

Coverage decreased (-0.0007%) to 93.999% when pulling c77f576 on doc-config-formatting into f901396 on main.