docs: Add documentation about code review by step

[jan-goral]

This pull request adds a missing page about code review to documentation.

[mergify]

Title does not follow the guidelines of Conventional Commits.
Please adjust title before merge and use one of following prefix:

• build - Changes that affect the build system or external dependencies (dependencies update)
• ci - Changes to our CI configuration files and scripts (basically directory .github/workflows)
• docs - Documentation only changes
• feat - A new feature
• fix - A bug fix
• chore - Changes which does not touch the code (ex. manual update of release notes). It will not generate release notes changes
• refactor - A code change that contains refactor
• style - Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• test - Adding missing tests or correcting existing tests and also changes for our test app
• perf - A code change that improves performance (I do not think we will use it)

[codecov-io]

Codecov Report

Merging #1355 (d573cfa) into master (3075194) will increase coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1355      +/-   ##
============================================
+ Coverage     77.79%   77.81%   +0.02%     
  Complexity      705      705              
============================================
  Files           244      244              
  Lines          4692     4692              
  Branches        901      901              
============================================
+ Hits           3650     3651       +1     
  Misses          550      550              
+ Partials        492      491       -1     

[github-actions]

Timestamp: 2020-11-26 10:37:01
Buildscan url for ubuntu-workflow run 384308728
https://gradle.com/s/gomeuxrqxslii