docs: update federation diagrams to include connectors (#3219)

Update diagrams for the federation conceptual page

Author: Meschreiber

docs/source/images/federation-dark.svg

@@ -13,7 +13,7 @@ Clients makes requests to the federated GraphQL API's single entry point called
 <img src='../../images/federation.svg' class="dark:hidden"/>
 <img src='../../images/federation-dark.svg' class="hidden dark:block"/>
 
-Your federated GraphQL API, or _graph_, can be made of GraphQL APIs, REST APIs, and other data sources.
+Your federated GraphQL API, or _graph_, can be made of GraphQL APIs, REST APIs, and other data sources. The router connects to REST APIs via Apollo Connectors and can connect to other data sources via GraphQL APIs. 
 
 <ExpansionPanel title="Watch the video overview">