add Connections crosslinks to Existing app tutorial

Signed-off-by: Will Tsai <[email protected]>

docs/content/tutorials/tutorial-add-radius/index.md

@@ -321,4 +321,5 @@ This output shows that Radius has detected the three container resources in the
 
 - To learn more about authoring Radius applications, visit the [Authoring applications guide]({{< ref "guides/author-apps" >}})
 - To learn more about deploying applications using Radius, visit the [Deploying applications guide]({{< ref "guides/deploy-apps" >}})
+- To learn more about using [Radius Connections]({{< ref "guides/author-apps/containers/overview#connections" >}}) to connect your containers and resources, visit the [Connect to dependencies guide]({{< ref "guides/author-apps/containers/howto-connect-dependencies" >}})
 - To learn more about Radius Recipes, visit the [Recipes guide]({{< ref "guides/recipes" >}})