Make PersonCard#memberships docs less ambiguous

The use of the word "current" was a bit misleading in this context, it
could mean either the current page this class is being used on or the
current term that's in session right now.

lib/person_cards.rb

@@ -58,7 +58,7 @@ def identifiers
     Section::Identifiers.new(person, top_identifiers: top_identifiers).data
   end
 
-  # List of memberships this person holds in the current term
+  # List of memberships this person held in this term
   # @return [Array<EveryPolitician::Popolo::Membership>]
   def memberships
     person.memberships.where(legislative_period_id: term.id)