Add missing yaml identifier to enable code highlighting
@@ -107,7 +107,7 @@ See the [example](example) folder.
By setting `services[].graphql` to true, the body will automatically be wrapped by the standard GraphQL `query` parameter.
For instance, the following configuration:
-```
+```yaml
services:
- name: filter users by gender
url: http://localhost:8080/playground
