Update Documentation for Routable Protocol

[viewDidAppear]

This change has been made to take advantage of the /// header-doc functionality in Xcode. Holding down Option while clicking on the method signatures of the Routable protocol will now provide further insight as to what needs to be supplied, and how it must be implemented to ensure fatalError() does not get triggered at runtime.

[codecov-io]

Codecov Report

Merging #84 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #84   +/-   ##
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  Coverage   80.28%   80.28%           
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  Files           5        5           
  Lines         208      208           
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  Hits          167      167           
  Misses         41       41

Impacted Files	Coverage Δ
ReSwiftRouter/Routable.swift	0% <ø> (ø)	:arrow_up:

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[DivineDominion]

@hlineholm Since you were working on the protocol last, do you have time to incorporate docstrings like this? E.g. rebase this PR and adjust?

[hlineholm]

Yes @DivineDominion if a get a slot in my calendar I will. Not my highest priority at the moment though.