Add index page to 'sqla' and 'layout' examples.

examples/layout/templates/admin/index.html

+{% extends 'admin/master.html' %}
+{% block body %}
+{{ super() }}
+<div class="row-fluid">
+    <h1>Flask-Admin example</h1>
+    <p class="lead">
+        Customize the layout
+    </p>
+    <p>
+        This example shows how you can customize the look & feel of the admin interface.
+    </p>
+    <p>
+        This is done by overriding some of the built-in templates.
+    </p>
+    <a class="btn btn-primary" href="/"><i class="icon-arrow-left icon-white"></i> Back</a>
+</div>
+{% endblock body %}
\ No newline at end of file

examples/sqla/templates/admin/index.html

+{% extends 'admin/master.html' %}
+{% block body %}
+{{ super() }}
+<div class="row-fluid">
+    <h1>Flask-Admin example</h1>
+    <p class="lead">
+        Basic SQLAlchemy model views.
+    </p>
+    <p>
+        This example shows how to add basic CRUD-views for your SQLAlchemy models.
+    </p>
+    <p>
+        The views are generated automatically, but it is perfectly possible to customize them to suit your needs.
+    </p>
+    <a class="btn btn-primary" href="/"><i class="icon-arrow-left icon-white"></i> Back</a>
+</div>
+{% endblock body %}
\ No newline at end of file