Fix UPDATE clause in MERGE USING grammar

h2/src/docsrc/help/help.csv

@@ -61,9 +61,7 @@ INSERT INTO TEST VALUES(1, 'Hello')
 "
 
 "Commands (DML)","UPDATE","
-UPDATE tableName [ [ AS ] newTableAlias ] SET
-{ { columnName = { DEFAULT | expression } } [,...] } |
-    { ( columnName [,...] ) = ( select ) }
+UPDATE tableName [ [ AS ] newTableAlias ] SET setClauseList
 [ WHERE expression ] [ ORDER BY order [,...] ] [ LIMIT expression ]
 ","
 Updates data in a table.
@@ -129,7 +127,8 @@ MERGE INTO TEST KEY(ID) VALUES(2, 'World')
 MERGE INTO targetTableName [ [AS] targetAlias]
 USING { ( select ) | sourceTableName }[ [AS] sourceAlias ]
 ON ( expression )
-[ WHEN MATCHED THEN [ update ] [ delete] ]
+[ WHEN MATCHED THEN
+    [ UPDATE SET setClauseList ] [ delete ] ]
 [ WHEN NOT MATCHED THEN insert ]
 ","
 Updates or deletes existing rows, and insert rows that don't exist. The ON clause
@@ -2438,6 +2437,15 @@ An expression in a SELECT statement.
 ID AS VALUE
 "
 
+"Other Grammar","Set clause list","
+{ { columnName = { DEFAULT | expression } } [,...] } |
+    { ( columnName [,...] ) = ( select ) }
+","
+List of SET clauses.
+","
+NAME = 'Test', VALUE = 2
+"
+
 "Other Grammar","String","
 'anythingExceptSingleQuote'
 ","