Option grouping

[chfw]

Before raising the PR, here is a check list:

• have you written unit tests for your code changes?
• have you updated the change log?
• can someone else understand your changes without your explanation?
• are you proud of your code changes?
• please add your name and github link to contributors.rst in alphabetical order.

[codecov-io]

Codecov Report

Merging #338 into dev will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##              dev     #338      +/-   ##
==========================================
+ Coverage   95.94%   95.94%   +<.01%     
==========================================
  Files          51       51              
  Lines        2614     2616       +2     
==========================================
+ Hits         2508     2510       +2     
  Misses        106      106

Impacted Files	Coverage Δ
moban/constants.py	100% <ø> (ø)	⬆️
moban/_version.py	100% <100%> (ø)	⬆️
moban/main.py	99.23% <100%> (+0.01%)	⬆️

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