fix: use showCommandHelp to delegate topic help

[RasPhilCo]

No description provided.

[codecov]

Codecov Report

Merging #58 into master will decrease coverage by 6.63%.
The diff coverage is 54.16%.

@@            Coverage Diff             @@
##           master      #58      +/-   ##
==========================================
- Coverage   69.93%   63.29%   -6.64%     
==========================================
  Files           4        5       +1     
  Lines         143      158      +15     
  Branches       29       35       +6     
==========================================
  Hits          100      100              
- Misses         27       39      +12     
- Partials       16       19       +3

Impacted Files	Coverage Δ
src/util.ts	38.88% <37.5%> (ø)
src/command.ts	76.25% <87.5%> (+1.58%)	⬆️
src/index.ts	35.71% <0%> (-41.56%)	⬇️

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[RasPhilCo]

@jdxcode single-cli help didn't have a trailing newline

[jdx]

looks like a good solution other than the imports which I think can be easily addressed