Minor doc fixes. Thanks @vmx

Change-Id: I332f5162b6aad5d23c20341ad0281672c76f9277
Reviewed-on: http://review.couchbase.org/25767
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Reviewed-by: Matt Ingenthron <matt@couchbase.com>