wave 4: Add a transition statement from experimentation into coding

Author: jmaddox19

ada-project-docs/wave_04.md

@@ -151,6 +151,8 @@ Press "Send" and see the Slack message come through!
 
 ### Modify `/tasks/<task_id>/mark_complete` to Call the Slack API
 
+Now that we've verified that we can successfully make a request to the Slack API, let's write some code to automatically call the Slack API from the API we've created!
+
 Given a task that has:
 
 - An id `1`