fix: handle exit on windows, closing cmd window

[shellscape]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

On windows users are prone to closing the CMD Window that serve is running in. That causes the processes to continue, resulting an in EACCESS port in use error the next time serve is run.

Breaking Changes

None

Additional Info

[codecov]

Codecov Report

Merging #110 into master will increase coverage by 0.12%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #110      +/-   ##
==========================================
+ Coverage   92.43%   92.56%   +0.12%     
==========================================
  Files           7        7              
  Lines         291      296       +5     
==========================================
+ Hits          269      274       +5     
  Misses         22       22

Impacted Files	Coverage Δ
index.js	96.15% <100%> (+0.4%)	⬆️

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