docs: update out of date Cloud information (meltano#7612)

Co-authored-by: Will Da Silva <will@willdasilva.xyz>

docs/src/_cloud/onboarding.md

@@ -151,9 +151,3 @@ To view logs for any completed or still-running job, you can use:
 ```console
 meltano-cloud logs print --execution-id=ASDF1234...
 ```
-
-## Additional Resources
-
-- [Known Issues and Feature Limitations](/known_issues)
-- [Security Whitepaper (Latest)](/security)
-- [Roles and Permissions](/platform/#roles-and-permissions)

docs/src/_cloud/platform.md

@@ -2,6 +2,8 @@
 title: "Platform Information"
 layout: doc
 weight: 5
+redirect_from:
+  - /cloud/reserved_variables
 ---
 
 <div class="notification is-info">
@@ -55,16 +57,8 @@ SOME_OTHER_SECRET=1234asdf
 
 Then continue with encryption using the [kms-ext](https://github.com/meltano/kms-ext) utility.
 
-## Roles and Permissions
+## Job or Schedule Run Notifications via Webhook
 
-### Role descriptions
+`MELTANO_CLOUD_WEBHOOK_URL` can be set to receive notifications on success or fail of a job or schedule run.
 
-- Users with the `owner` role access can create and delete projects, as well as performing all functions of `maintaner`. Owners can also view billing history and perform other account management functions, such as adding new users.
-- Users with the `maintaner` role access can perform normal development and maintenance functions, such as updating schedules and executing jobs. Maintainers cannot add or delete projects or users.
-- Users with the `reader` role only have read-only access: for instance, to view job statuses and summary logs.
-
-### Future updates
-
-Note:
-
-- More advanced role-based access permissions may be added in future versions on Meltano Cloud.
+Currently only one webhook URL can be configured.