Add mdbook site

[Luni-4]

This PR closes the last item of #139. It addresses the following problems:

• Explain the most common commands and provide some information about rust-code-analysis
• Implement a shell script to automatically deploy the site on GitHub Pages
• Create a temporary directory containing the documentation of rust-code-analysis (if the crate will be released on crates.io, that directory won't be no more necessary and subsequently removed)
• Update README

You can find the final results here

Thanks in advance for your review! :)

[Luni-4]

Removed the great amount of files used as documentation

[codecov-commenter]

Codecov Report

Merging #176 into master will increase coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #176      +/-   ##
==========================================
+ Coverage   15.84%   15.87%   +0.03%     
==========================================
  Files          44       44              
  Lines        5448     5448              
  Branches      597      597              
==========================================
+ Hits          863      865       +2     
+ Misses       4304     4301       -3     
- Partials      281      282       +1     

Impacted Files	Coverage Δ
src/metrics/loc.rs	46.28% <0.00%> (+1.65%)	⬆️

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[calixteman]

Thx for this work