Missing documentation added

Author: Webklex

README.md

@@ -92,7 +92,7 @@ Detailed [config/imap.php](src/config/imap.php) configuration:
   - `options` — additional fetch options
     - `delimiter` — you can use any supported char such as ".", "/", etc
     - `fetch` — `FT_UID` (message marked as read by fetching the message) or `FT_PEEK` (fetch the message without setting the "read" flag)
-    - `open` — => [
+    - `open` — special configuration for imap_open()
       - `DISABLE_AUTHENTICATOR` — Disable authentication properties.
 
 ## Usage