Update gitignore by including the documentation folder generated for Mondrian

[Valentin-Laurent]

Description

See title. Very small PR, not sure about how to update the history.rst, feedback welcome.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• I have read the contributing guidelines
• I have updated the HISTORY.rst and AUTHORS.rst files
• Linting passes successfully : make lint
• Typing passes successfully : make type-check
• Unit tests pass successfully : make tests
• Coverage is 100% : make coverage
• Documentation builds successfully : make doc

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (614293e) to head (6846dc1).
Report is 782 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##            master      #515     +/-   ##
===========================================
  Coverage   100.00%   100.00%             
===========================================
  Files           39        62     +23     
  Lines         4616      5994   +1378     
  Branches       487       987    +500     
===========================================
+ Hits          4616      5994   +1378     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.