Collapse changelog to one line

Signed-off-by: Jason Robinson <jasonr@matrix.org>

changelog.d/4420.feature

-New listener resource for the federation API "openid/userinfo" endpoint
-
-Integration managers use the OpenID userinfo endpoint in the federation API to verify that user
-OpenID access tokens are valid. If the federation resource is disabled, integration managers will not be able
-to verify the access token, causing a broken experience for users. The OpenID userinfo endpoint has now been split
-to a separate `openid` resource, which is enabled by default in newly generated configuration. It is also enabled
-automatically if the federation resource is enabled.
-
-If your homeserver runs federation enabled, this change does not require any actions.
-
-If you run a homeserver with federation disabled, we recommend adding the `openid` resource to your homeserver
-configuration in the `type: http` listener `resources` list to allow your users access to
-integration manager features.
+Federation OpenID listener resource can now be activated even if federation is disabled