[unord.multiset.overview] Fix presentation of member types

Author: jensmaurer

source/containers.tex

@@ -12603,7 +12603,7 @@
 It provides the operations described in the
 preceding requirements table for equivalent keys; that is, an \tcode{unordered_multiset}
 supports the \tcode{a_eq} operations in that table, not the \tcode{a_uniq} operations.
-For an \tcode{unordered_multiset<Key>} the \tcode{key type} and the value type are
+For an \tcode{unordered_multiset<Key>} the \tcode{key_type} and the \tcode{value_type} are
 both \tcode{Key}. The \tcode{iterator} and \tcode{const_iterator} types are both
 constant iterator types. It is unspecified whether they are the same type.