Grammar/wording tweaks for coll.update().

Signed-off-by: kay <kay.kim@10gen.com>
Update a coll.update() example to use a different db.bios record

The document in the bios example collection with {_id: 6} doesn't
actually contain an 'awards.by: ACM' field, so I updated the example
with a document that does.

Signed-off-by: kay <kay.kim@10gen.com>