Resolve "Update feature list in README"

Closes #535 (closed)

README.rst

@@ -31,6 +31,7 @@ The AlekSIS core currently provides the following features:
  * Two factor authentication via Yubikey, OTP or SMS
  * User preferences
  * User registration, password changes and password reset
+ * User invitations with invite codes and targeted invites
 
 * For admins
 
@@ -41,6 +42,8 @@ The AlekSIS core currently provides the following features:
  * OAuth2 and OpenID Connect provider support
  * Serve prometheus metrics
  * System health and data checks
+ * Support config files in JSON format
+ * Notication via Mail if tasks do failure
 
 * For developers
 
@@ -53,6 +56,7 @@ The AlekSIS core currently provides the following features:
  * Query caching with `django-cachalot`
  * Search with `django-haystack` and `Whoosh` backend
  * uWSGI and Celery via `django-uwsgi` in development
+ * Install system and build dependencies in docker build
 
 Licence
 -------