Add documentation for the `severed_relationships` event type

content/en/entities/Notification.md

@@ -35,13 +35,15 @@ aliases: [
 `update` = A status you interacted with has been edited\
 `admin.sign_up` = Someone signed up (optionally sent to admins)\
 `admin.report` = A new report has been filed\
+`severed_relationships` = Some of your follow relationships have been severed as a result of a moderation or block event\
 **Version history:**\
 0.9.9 - added\
 2.8.0 - added `poll`\
 3.1.0 - added `follow_request`\
 3.3.0 - added `status`\
 3.5.0 - added `update` and `admin.sign_up`\
-4.0.0 - added `admin.report`
+4.0.0 - added `admin.report`\
+4.3.0 - added `severed_relationships`
 
 ### `created_at` {#created_at}
 
@@ -71,6 +73,13 @@ aliases: [
 **Version history:**\
 4.0.0 - added
 
+### `relationship_severance_event` {{%optional%}} {#relationship_severance_event}
+
+**Description:** Summary of the event that caused follow relationships to be severed. Attached when `type` of the notification is `severed_relationships`.\
+**Type:** [RelationshipSeveranceEvent]({{< relref "entities/RelationshipSeveranceEvent" >}})\
+**Version history:**\
+4.3.0 - added
+
 ## Examples
 
 ### Mention