Merge pull request #427 from datamweb/add-features-to-readme

docs: add some important shield features to `README.md`

Author: kenjis

README.md

@@ -29,6 +29,18 @@ These are much like the access codes that GitHub uses, where they are unique to
 can have more than one. This can be used for API authentication of third-party users, and even for allowing
 access for a mobile application that you build.
 
+## Some Important Features
+
+* Session-based authentication (traditional email/password with remember me)
+* Stateless authentication using Personal Access Tokens
+* Optional Email verification on account registration
+* Optional Email-based Two Factor Authentication after login
+* Magic Login Links when a user forgets their password
+* Flexible groups-based access control (think roles, but more flexible)
+* Users can be granted additional permissions
+
+See the [An Official Auth Library](https://codeigniter.com/news/shield) for more Info.
+
 ## Getting Started
 
 ### Prerequisites