Notification: add a counter for notifications

src/Bundle/ChillMainBundle/translations/messages+intl-icu.fr.yaml

@@ -1,6 +1,15 @@
 years_old: >-
-    {age, plural, 
+    {age, plural,
         one {# an}
         many {# ans}
         other {# ans}
     }
+
+notification:
+    My notifications with counter: >-
+        {nb, plural,
+            =0 {Mes notifications}
+            one {Une notification}
+            few {# notifications}
+            other {# notifications}
+        }