In part this change is motivated by issue #14, in which @storge pointed out that
the ppl show command only displays one of the contact's email addresses. This
gives the impression that only one can be stored per contact, so it needed
Another reason for this change was that the output of ppl show was on the whole
quite an ugly, disorganised mess. This commit changes the rest of the formatting
somewhat so that hopefully it'll be a little more clear.