Fix ChangeHistoryService typo

Author: joritochip

content/en-us/reference/engine/classes/ChangeHistoryService.yaml

@@ -291,10 +291,11 @@ events:
         default:
         summary: |
           The identifier for the recording.
-      - name: operationn
+      - name: operation
         type: FinishRecordingOperation
         default:
-        summary: ''
+        summary: |
+          Specifies the operation that was taken.
       - name: finalOptions
         type: Dictionary?
         default: