Update README.md

README.md

@@ -20,6 +20,6 @@ template generation: <question> | <db_id> | <schema_without_content>
 ```
 The output format is
 ```
-<J> joins @ <S> selects @ <template>
+<db_id> | <J> joins @ <S> selects @ <template>
 ```
 The plan at the beginning is used to enforce diversity as described in our paper. A typical template looks like `SELECT column, column FROM table AS t1 JOIN table AS t2`.