Update docs/cases/cases-manage-settings.asciidoc

Co-authored-by: natasha-moore-elastic <[email protected]>

Author: nastasha-solomon

docs/cases/cases-manage-settings.asciidoc

@@ -136,7 +136,7 @@ To use observables, you must have a https://www.elastic.co/pricing[Platinum subs
 
 Create custom observable types for enhanced case collaboration.
 
-. In the *Observable types* section, click *Add observable*.
+. In the *Observable types* section, click *Add observable type*.
 . Enter a descriptive label for the observable type, then click *Save*.
 
 After creating a new observable type, you can remove or edit it from the **Settings** page.