Adjusted Pushover notes for clarity on behaviour

README.md

@@ -310,14 +310,26 @@ To enable Discord integration, you will need to:
 
 ### Pushover
 
+Pushover integration works by creating an 'application' on Pushover.net which
+is then subscribed to by Healthchecks users. Registration workflow is as follows:
+
+* On Healthchecks, user adds a 'Pushover' integration to a project
+* Healthchecks redirects to a Pushover.net subscription page
+* User approves adding the Healthchecks subscription to their pushover account
+* Pushover.net HTTP redirects back to Healthchecks with a subscription token
+* Healthchecks instance uses subscription token for Pushover notifications
+
 To enable Pushover integration, you will need to:
 
-* register a new application on https://pushover.net/apps/build
-* enable subscriptions in your application and make sure to enable the URL
-  subscription type
-* put the application token and the subscription URL in
+* Register a new 'application' on Pushover via https://pushover.net/apps/build .
+* Within the Pushover 'application' configuration, enable subscriptions. 
+  Make sure to subscription type is set to 'URL'. Also make sure the redirect 
+  URL is configured to point back to the root of the Healthchecks instance
+  (eg http://healthchecks.example.com/).
+* Add the Pushover application API Token and the Pushover subscription URL in
   `PUSHOVER_API_TOKEN` and `PUSHOVER_SUBSCRIPTION_URL` environment
-  variables
+  variables. The pushover subscription URL should appear similar to
+  https://pushover.net/subscribe/yourAppName-randomAlphaNumericData .
 
 ### Telegram