Update changelog

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Add support for 'enchant' spellcheck engine
 - Fix "could not load message" error on valid empty message body (#1489228)
 - Check filetype detection in installer and update script (#1489193)
 - Fix handling of message/rfc822 attachments on message forward and edit (#1489214)

config/main.inc.php.dist

@@ -512,8 +512,9 @@ $rcmail_config['enable_spellcheck'] = true;
 // Setting it to 'shared' will make the dictionary shared by all users.
 $rcmail_config['spellcheck_dictionary'] = false;
 
-// Set the spell checking engine. 'googie' is the default. 'pspell' is also available,
-// but requires the Pspell extensions. When using Nox Spell Server, also set 'googie' here.
+// Set the spell checking engine. 'googie' is the default.
+// 'pspell' and 'enchant' are also available, but they require
+// PHP Pspell or Enchant extensions. When using Nox Spell Server, also set 'googie' here.
 $rcmail_config['spellcheck_engine'] = 'googie';
 
 // For a locally installed Nox Spell Server, please specify the URI to call it.