Updated Notification configuration notes (markdown)

Notification-configuration-notes.md

@@ -1,3 +1,6 @@
 - Using @ in your mailtos/smtps password, see https://github.com/caronc/apprise/issues/400
 - Be sure that your notification body contains atleast something, often `{base_url}` will be empty, an empty notification body often causes problems with many notification targets
-- Make sure you're not exceeding your target notification service message length when using {current_snapshot} token
+- Make sure you're not exceeding your target notification service message length when using {current_snapshot} token
+
+## Discord
+There's a limit of 2,000 characters total notification length  (See https://github.com/dgtlmoon/changedetection.io/issues/323)