Consistent with this idea would be something like the "I feel lucky" search
on Google, i.e. ?foo would go immediately to the best match, while ??foo
would present a list of possible matches. This is not consistent with
current behaviour, where ?foo will present a list if it matches two or more
topics, but I think we can always rank one ahead of the other based on their
ordering in the search list. I don't know if it will be so easy to rank
hits coming from help.search(), or from other searches that don't exist yet:
but maybe it doesn't matter. If someone doesn't like what they get from
?foo, they can always try ??foo.