Add update photo feature to Developer Guide

[VN-Hao]

Closes #153

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (ec1d68c) 82.78% compared to head (a9b2b44) 82.78%.

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #155   +/-   ##
=========================================
  Coverage     82.78%   82.78%           
  Complexity      755      755           
=========================================
  Files            99       99           
  Lines          2312     2312           
  Branches        259      259           
=========================================
  Hits           1914     1914           
  Misses          333      333           
  Partials         65       65           

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[limjunxian1]

Overall, LGTM! seems like you followed the format and flow of content as per notes feature. We can always take the formatting and layout of our content in DG to be settled in 1.4. Happy to merge this for now due to the time limitations of 1.3b! Just a few pointers to keep in mind and we can work towards:

1. Sequence diagram can afford to omit low level details
2. Design considerations to be inserted into your section. You can refer to other features that already elaborates on them for a rough guideline.