Added a tutorial

_sources/index.txt

@@ -1,3 +1,5 @@
+.. image:: _static/img/caravel.jpg
+
 .. warning:: This project used to be name Panoramix and has been renamed
     to Caravel in March 2016
 
@@ -8,17 +10,17 @@ Features
 ---------
 
 - A rich set of data visualizations, integrated from some of the best
-    visualization libraries
+  visualization libraries
 - Create and share simple dashboards
 - An extensible, high-granularity security/permission model allowing
-    intricate rules on who can access individual features and the dataset
+  intricate rules on who can access individual features and the dataset
 - Enterprise-ready authentication with integration with major authentication
-    providers (database, OpenID, LDAP, OAuth & REMOTE_USER through
-    Flask AppBuilder)
+  providers (database, OpenID, LDAP, OAuth & REMOTE_USER through
+  Flask AppBuilder)
 - A simple semantic layer, allowing users to control how data sources are
-    displayed in the UI by defining which fields should show up in which
-    drop-down and which aggregation and function metrics are made available
-    to the user
+  displayed in the UI by defining which fields should show up in which
+  drop-down and which aggregation and function metrics are made available
+  to the user
 - Integration with most RDBMS through SqlAlchemy
 - Deep integration with Druid.io
 
@@ -29,7 +31,8 @@ Contents
     :maxdepth: 2
 
     installation
-    user_guide
+    tutorial
+    videos
 
 
 Indices and tables