style fixes for examples README (#162)

examples/README.md

@@ -89,18 +89,18 @@ This example shows how to inject middleware between the generated `PGClient` and
 connection. This allows you to implement things like logging and tracing to see what queries
 are getting run against the database.
 
-### [Example: single results](single_results)
+### [Example: single_results](single_results)
 
 This example shows how to write queries that return just a single row as a result using
 the `single_result` configuration option. This is a small quality of life improvement over
 having to unpack a slice each time you place a query.
 
-## [Example: json_columns](json_columns)
+### [Example: json_columns](json_columns)
 
 This example shows how to ask pggen to generate conversion code between arbitrary go
 types and `json` or `jsonb` types in postgres.
 
-## [Example: nullable_query_arguments](nullable_query_arguments)
+### [Example: nullable_query_arguments](nullable_query_arguments)
 
 This example show how to ask pggen to generate code which allows nils to be passed into
 queries. By default, you can only pass concrete types like `string` and `int` into a