small tweak to document lookup field
small tweak to document lookup field

Change-Id: I6b422ff34567788531c3825a586589fecb5f7055
Reviewed-on: http://review.couchbase.org/8606
Reviewed-by: Dale Harvey <491ccac09a36ad1e38b698f273b84fd8efc31071@arandomurl.com>
Tested-by: Dale Harvey <491ccac09a36ad1e38b698f273b84fd8efc31071@arandomurl.com>

daverigby/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,membase/ns_server,pavel-blagodov/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,ceejatec/ns_server,ceejatec/ns_server,daverigby/ns_server,nimishzynga/ns_server,vzasade/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,nimishzynga/ns_server,ceejatec/ns_server,daverigby/ns_server,vzasade/ns_server,mschoch/ns_server,daverigby/ns_server,vzasade/ns_server,mschoch/ns_server,nimishzynga/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,daverigby/ns_server,ceejatec/ns_server,membase/ns_server,vzasade/ns_server,membase/ns_server