add warning text for .env.example

.env.example

@@ -1,10 +1,11 @@
 # Keys
 # Required key for platform encryption/decryption ops
-# THIS IS A SAMPLE ENCRYPTION KEY AND SHOULD NOT BE USED FOR PRODUCTION
+# THIS IS A SAMPLE ENCRYPTION KEY AND SHOULD NEVER BE USED FOR PRODUCTION
 ENCRYPTION_KEY=6c1fe4e407b8911c104518103505b218
 
 # JWT
 # Required secrets to sign JWT tokens
+# THIS IS A SAMPLE AUTH_SECRET KEY AND SHOULD NEVER BE USED FOR PRODUCTION
 AUTH_SECRET=5lrMXKKWCVocS/uerPsl7V+TX/aaUaI7iDkgl3tSmLE=
 
 # MongoDB