Changes to docs

doc/api/labels.md

@@ -285,6 +285,10 @@ Example response:
 NOTE: **Note:**
 An older endpoint `PUT /projects/:id/labels/promote` with `name` in the parameters is still available, but deprecated.
 
+NOTE: **Note:**
+As of GitLab 13.6, promoting a project label keeps that label's ID and changes it into a group label.
+Previously, promoting a project label created a new group label with a new ID and deleted the old label.
+
 ## Subscribe to a label
 
 Subscribes the authenticated user to a label to receive notifications.

doc/user/project/labels.md

@@ -114,6 +114,10 @@ To promote a project label to a group label:
 1. Click on the three dots (**{ellipsis_v}**) next to the **Subscribe** button and
    select **Promote to group label**.
 
+NOTE: **Note:**
+As of GitLab 13.6, promoting a project label keeps that label's ID and changes it into a group label.
+Previously, promoting a project label created a new group label with a new ID and deleted the old label.
+
 ### Group labels
 
 To view the group labels list, navigate to the group and click **Issues > Labels**.