The docs can be built by running "make" from the docs directory. This
does not hook into buildall.sh for now, as users who run buildall.sh
do not usually edit docs/.
Change-Id: I9551b75268cb7cb29a58367a3ef03b127dccbfca
Reviewed-on: http://gerrit.cloudera.org:8080/5238
Reviewed-by: Tim Armstrong <tarmstrong@cloudera.com>
Reviewed-by: Greg Rahn <grahn@cloudera.com>
Tested-by: Jim Apple <jbapple-impala@apache.org>
