Update docs/docs/concepts/domain.mdx

Co-authored-by: Maxime Vdb <[email protected]>

docs/docs/concepts/domain.mdx

@@ -32,7 +32,7 @@ rasa train --domain path_to_domain_directory
 
 ## Responses
 
-Responses are actions that send a message to a user without running any custom code or
+Responses are [actions](#actions) that send a message to a user without running any custom code or
 returning events. These responses can be defined directly in the domain file under the `responses` key
 and can include rich content such as buttons and attachments. For more information on responses and how to define them,
 see [Responses](./responses.mdx).