Update base-url docs

docs/releases.md

@@ -22,6 +22,8 @@ and the [ntfy Android app](https://github.com/binwiederhier/ntfy-android/release
 
 * Added [example](examples.md) for [Uptime Kuma](https://github.com/louislam/uptime-kuma) integration ([#315](https://github.com/binwiederhier/ntfy/pull/315), thanks to [@philippdormann](https://github.com/philippdormann))
 * Fix Docker install instructions  ([#320](https://github.com/binwiederhier/ntfy/issues/320), thanks to [@milksteakjellybeans](https://github.com/milksteakjellybeans) for reporting)
+* Add clarifying comments to base-url ([#322](https://github.com/binwiederhier/ntfy/issues/322), thanks to [@milksteakjellybeans](https://github.com/milksteakjellybeans) for reporting)
+
 
 ## ntfy iOS app v1.2 (UNRELEASED)
 

server/server.yml

@@ -4,7 +4,8 @@
 # All options also support underscores (_) instead of dashes (-) to comply with the YAML spec.
 
 # Public facing base URL of the service (e.g. https://ntfy.sh or https://ntfy.example.com)
-# This setting is currently only used by the attachments and e-mail sending feature (outgoing mail only).
+# This setting is currently only used by attachments, e-mail sending (outgoing mail only), as well
+# as in combination with upstream-base-url (for iOS push notifications for self-hosted servers).
 #
 # base-url: