Update docs with the new --help argument

[victorphoenix3]

Fixes #124

[codecov]

Codecov Report

Merging #135 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master      #135   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          242       242           
  Lines         4504      4508    +4     
=========================================
+ Hits          4504      4508    +4     

Impacted Files	Coverage Δ
docs_src/testing/app01/main.py	100.00% <0.00%> (ø)
docs_src/options/version/tutorial003.py	100.00% <0.00%> (ø)
docs_src/parameter_types/bool/tutorial002.py	100.00% <0.00%> (ø)
docs_src/parameter_types/path/tutorial001.py	100.00% <0.00%> (ø)

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[victorphoenix3]

@tiangolo @Kludex This is ready for review.
The PR was initially failing build, had to run format.sh hence the large size of the PR.

[Kludex]

Suggested change

	[NAMES]... Select 3 characters to play with [default: Harry, Hermione,Ron]
	[NAMES]... Select 3 characters to play with [default: Harry, Hermione, Ron]

[tiangolo]

Thanks @victorphoenix3 ! 🚀 🍰

And thanks @Kludex for the review! ☕