Update contribution docs, include istio's bookinfo

[nirvanagit]

1. Restructure and update contribution doc,
2. Include modified bookinfo from Istio. The modifications are done to enable Admiral to start watching them

[codecov-commenter]

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.75%. Comparing base (182ccab) to head (7d2ab00).

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Additional details and impacted files

@@           Coverage Diff           @@
##           master     #354   +/-   ##
=======================================
  Coverage   71.75%   71.75%           
=======================================
  Files          66       66           
  Lines        9446     9446           
=======================================
  Hits         6778     6778           
  Misses       2295     2295           
  Partials      373      373           

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[aattuluri]

Why copy the whole file?

[nirvanagit]

Good point, let me just add the required annotation instead.