add Separate multiple email addresses with commas to en.json

src/lang/en.json

@@ -1052,5 +1052,6 @@
     "Can be found on:": "Can be found on: {0}",
     "The phone number of the recipient in E.164 format.": "The phone number of the recipient in E.164 format.",
     "Either a text sender ID or a phone number in E.164 format if you want to be able to receive replies.":"Either a text sender ID or a phone number in E.164 format if you want to be able to receive replies.",
-    "SendGrid API Key": "SendGrid API Key"
+    "SendGrid API Key": "SendGrid API Key",
+    "Separate multiple email addresses with commas": "Separate multiple email addresses with commas"
 }