Fix description of archive format which pg_restore -j supports.

doc/src/sgml/ref/pg_restore.sgml

@@ -265,8 +265,9 @@
        </para>
 
        <para>
-        Only the custom archive format is supported with this option.
-        The input file must be a regular file (not, for example, a
+        Only the custom and directory archive formats are supported
+        with this option.
+        The input must be a regular file or directory (not, for example, a
         pipe).  This option is ignored when emitting a script rather
         than connecting directly to a database server.  Also, multiple
         jobs cannot be used together with the