Add optionnal description to circles

What needs to be done?

Today we have name and sub-titles for circles (that appears as description in the circle list). Sometimes, it's tempting to use the sub-title to put a whole paragraph of circle description. Having an additional description field would make this paragraph easier to read while still using the sub-title as short explanation of a one-word title.

Technical details

Description field should be optional.

Test cases

Screenshot example on ESS France :

Links & Mockups

Do we need some design here ? @sophie ?

Old accounting Protocol