Update toc.yml

fix spelling mistake

Author: valindrae

articles/communication-services/toc.yml

@@ -394,7 +394,7 @@ items:
       href: samples/trusted-auth-sample.md
   - name: Phone calling
     items:
-    - name: Appointment remainder sample
+    - name: Appointment reminder sample
       href: samples/call-automation-appointment-reminder.md
 - name: Concepts 
   items: