Improment PR guide lines

[sandokandias]

- What I did

As per the last meeting's presentation, I am updating the Contributing.md with some suggestion on how potential future codeowners might want to conduct pull reviews

- How to verify it

open Contributing.md

- Description for the changelog
Updated Contributing.md to include pull review guidelines

[codecov-commenter]

Codecov Report

Merging #328 into ritchie-2.0.0 will increase coverage by 0.02%.
The diff coverage is 0.00%.

@@                Coverage Diff                @@
##           ritchie-2.0.0     #328      +/-   ##
=================================================
+ Coverage          65.21%   65.24%   +0.02%     
=================================================
  Files                 78       78              
  Lines               2550     2552       +2     
=================================================
+ Hits                1663     1665       +2     
  Misses               725      725              
  Partials             162      162              

Impacted Files	Coverage Δ
pkg/credential/finder.go	68.42% <ø> (ø)
pkg/credential/settings.go	84.76% <0.00%> (-1.65%)	⬇️
pkg/formula/watcher/watcher.go	76.47% <0.00%> (+5.88%)	⬆️

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