Add a note to README about credentials API appeared in rails 5.2

README.md

@@ -57,7 +57,7 @@ require 'telegram/bot'
 
 ### Configuration in Rails app
 
-Add `telegram` section into `secrets.yml`:
+For Rails < 5.2 add `telegram` section into `secrets.yml`:
 
 ```yml
 development:
@@ -79,6 +79,8 @@ development:
         username: ChatBot
 ```
 
+For Rails > 5.2 edit credentials `EDITOR=nano rails credentials:edit`
+
 From now clients will be accessible with `Telegram.bots[:chat]` or `Telegram.bots[:auction]`.
 Single bot can be accessed with `Telegram.bot` or `Telegram.bots[:default]`.