add permissions details about CRUD for releases (#17034)

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## DESCRIBE YOUR PR
Updating the permissions needed for release operations, which were not
well documented previously and the behaviour has been improved.

## IS YOUR CHANGE URGENT?  
- [X] None: Pending getsentry/sentry#111021
deployment

## PRE-MERGE CHECKLIST

*Make sure you've checked the following before merging your changes:*

- [X] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

Author: geoffg-sentry

docs/api/permissions.mdx

@@ -82,3 +82,9 @@ Events in Sentry are immutable and can only be deleted by deleting the whole iss
 Be aware that if you're using `sentry-cli` to [manage your releases](/cli/releases/), you'll need a token which also has `org:read` scope.
 
 </Alert>
+
+<Alert level="info" title="Project Access">
+
+In addition to the `project:releases` scope, mutations on releases (create, update, delete, file uploads, deploys) require that the user has access to **all** projects associated with the release. If your organization has [Open Membership](/organization/membership/#open-membership) disabled, members can only modify releases for projects belonging to teams they are a member of.
+
+</Alert>