Kudu partition clause doc is wrong

The following line in the docs:

kudu_partition_clause ::= [hash_clause] [, range_clause [ , range_clause ] ]

which can be found here: https://impala.apache.org/docs/build/html/topics/impala_create_table.html

is incorrect. We support an unlimited number of hash clauses followed by either 0 or 1 range clauses, whereas the doc shows the opposite.