Update user_guide_src/source/database/query_builder.rst

Co-authored-by: kenjis <kenji.uui@gmail.com>

Author: iRedds

user_guide_src/source/database/query_builder.rst

@@ -305,6 +305,7 @@ methods:
     $builder->where($where);
 
 .. _query-builder-where-subquery:
+
 #. **Subqueries:**
 
     ::