Fix docs for JSON_TABLE(): replaceable => parameter

Author: Nikita Glukhov

doc/src/sgml/func.sgml

@@ -18612,8 +18612,8 @@ where <replaceable class="parameter">json_table_column</replaceable> is:
         [ PATH <replaceable>json_path_specification</replaceable> ]
         [ { WITHOUT | WITH { CONDITIONAL | [UNCONDITIONAL] } } [ ARRAY ] WRAPPER ]
         [ { KEEP | OMIT } QUOTES [ ON SCALAR STRING ] ]
-        [ { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT expression } ON EMPTY ]
-        [ { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT expression } ON ERROR ]
+        [ { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON EMPTY ]
+        [ { ERROR | NULL | EMPTY { ARRAY | OBJECT } | DEFAULT <replaceable>expression</replaceable> } ON ERROR ]
   | <replaceable>name</replaceable> <replaceable>type</replaceable> EXISTS [ PATH <replaceable>json_path_specification</replaceable> ]
         [ { ERROR | TRUE | FALSE | UNKNOWN } ON ERROR ]
   | NESTED PATH <replaceable>json_path_specification</replaceable> [ AS <replaceable>path_name</replaceable> ]