Correct the missing explanation on _('Entity assignment'), _('supannEntiteAffectation') in the supann plugin

Descriptive title for this enhancement

Correct the missing explanation on _('Entity assignment'), _('supannEntiteAffectation') in the supann plugin

Actual behaviour

actually there is no explanation for entity assignment on the supann plugin

Expected behaviour

Have a nice sentence that explain what the field is for

Benefits

More clear for the users using the supann plugin

Possible Drawbacks

none