Save timeline as new (#4437)

docs/events/timeline-ui-overview.asciidoc

@@ -12,7 +12,9 @@ by clicking *+ Add field*.
 [role="screenshot"]
 image::images/timeline-ui-updated.png[example Timeline with several events]
 
-To avoid losing your changes, you must save the Timeline before moving to a different {security-app} page. 
+To avoid losing your changes, you must save the Timeline before moving to a different {security-app} page.
+
+If you change an existing Timeline, you can use the **Save as new timeline** toggle to make a new copy of the Timeline, without overwriting the original one.
 
 TIP: You can record and share your findings with others by attaching your Timeline to a
 <<cases-overview, case>>.