updated postman screenshots to use JSON instead of query params

Author: Mikelle Wade

ada-project-docs/assets/postman_headers.png

@@ -135,12 +135,12 @@ Open Postman and make a request that mimics the API call to Slack that we just t
   - `channel`: `task-notifications`
   - `text`: Fill in a nice message
 
-![](assets/postman_test_JSON.png)
+![](assets/postman_request_body.png)
 
 - In "Headers," add this new key-value pair:
   - `Authorization`: `"Bearer xoxb-150..."`, where `xoxb-150...` is your full Slackbot token
 
-![](assets/postman_test_headers.png)
+![](assets/postman_headers.png)
 
 Press "Send" and see the Slack message come through!
 
@@ -191,6 +191,6 @@ Test and verify that your API sends an API call to the Slack web API by using Po
 
 Send `PATCH` requests to `localhost:5000/tasks/<book_id>/mark_complete` (use the ID of any existing task), and check if Slack messages were sent.
 
-![](assets/postman_feature.png)
+![](assets/postman_patch.png)
 
 ![](assets/slack_notification_feature.png)