add missing docs for EMAIL_FRONTEND_* settings

docs/source/emails.rst

@@ -9,3 +9,5 @@ Email support is now handled with the `django-templated-mail <https://github.com
 package.
 
 Email classes can be overridden using `EMAIL setting <http://djoser.readthedocs.io/en/latest/settings.html#email>`_
+
+If you need to customize the domain name in the email contents (fe. for user activation or password reset), see `EMAIL_FRONTEND_*` settings.

docs/source/settings.rst

@@ -58,6 +58,21 @@ You should pass ``uid`` and ``token`` to reset username confirmation endpoint.
 
 **Required**: ``True``
 
+EMAIL_FRONTEND_PROTOCOL
+-----------------------
+
+If set, it will replace the PROTOCOL part of the url in the emails content.
+
+EMAIL_FRONTEND_DOMAIN
+---------------------
+
+If set, it will replace the DOMAIN part of the url in the emails content.
+
+EMAIL_FRONTEND_SITE_NAME
+------------------------
+
+If set, it will replace the SITE_NAME in the emails content.
+
 SEND_ACTIVATION_EMAIL
 ---------------------