Updated README.md

README.md

@@ -1,6 +1,25 @@
-# Single Sign On for GLPI
+# Single Sign-On for GLPI
 
 [![Build Status](https://travis-ci.org/edgardmessias/glpi-singlesignon.svg?branch=master)](https://travis-ci.org/edgardmessias/glpi-singlesignon)
 [![CodeFactor](https://www.codefactor.io/repository/github/edgardmessias/glpi-singlesignon/badge)](https://www.codefactor.io/repository/github/edgardmessias/glpi-singlesignon)
 [![Total Downloads](https://img.shields.io/github/downloads/edgardmessias/glpi-singlesignon/total.svg)](https://github.com/edgardmessias/glpi-singlesignon/releases)
 [![Current Release](https://img.shields.io/github/release/edgardmessias/glpi-singlesignon.svg)](https://github.com/edgardmessias/glpi-singlesignon/releases/latest)
+
+Single sign-on (SSO) is a property of access control of multiple related, yet independent, software systems. With this property, a user logs in with a single ID and password to gain access to any of several related systems.
+
+# Installation
+ * Uncompress the archive to the `<GLPI_ROOT>/plugins/singlesignon` directory
+ * Navigate to the Configuration > Plugins page,
+ * Install and activate the plugin.
+
+# Usage
+ * Go to `Configuration > Single Sign-On` and add a provider
+ * To test, do logout and try login with links below login page `[ Login with <name> ]`
+
+# Available providers
+ * Facebook - https://developers.facebook.com/docs/apps/
+ * GitHub - https://developer.github.com/apps/building-oauth-apps/creating-an-oauth-app/
+ * Google - https://developers.google.com/identity/protocols/OpenIDConnect
+ * Instagram - https://www.instagram.com/developer/authentication/
+ * LinkedIn - https://docs.microsoft.com/en-us/linkedin/shared/authentication/authorization-code-flow?context=linkedin/context
+ * Generic - Allow to define custom URLs