[libgda] Added introduction to GdaData interfaces

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit c4367732a58b493a28db2f54c2f6c4877921c67d
Author: Daniel Espinosa <despinosa src gnome org>
Date:   Mon Mar 26 18:40:51 2012 -0600

    Added introduction to GdaData interfaces

 doc/mallard/gda-data/Interfaces.page    |    8 +++++++-
 doc/mallard/gda-data/interfaces-uml.png |  Bin 0 -> 35566 bytes
 2 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/doc/mallard/gda-data/Interfaces.page b/doc/mallard/gda-data/Interfaces.page
index c3bc76b..a8c74d9 100644
--- a/doc/mallard/gda-data/Interfaces.page
+++ b/doc/mallard/gda-data/Interfaces.page
@@ -17,8 +17,14 @@
     Interfaces
   </title>
   <p>
-  
+  Vala Extensions defines a set of interfaces to define a generic behaviour. They expect to be the base for future implementations for Vala objects accessing a database.
   </p>
   <p>
+  The interfaces defined are the following:
   </p>
+  <figure>
+  <title>UML diagram for Interfaces</title>
+  <desc>This diagram describes the available interfaces and its relations.</desc>
+  <media type="image" mime="image/png" src="interfaces-uml.png"/>
+</figure>
 </page>
diff --git a/doc/mallard/gda-data/interfaces-uml.png b/doc/mallard/gda-data/interfaces-uml.png
new file mode 100644
index 0000000..e41b871
Binary files /dev/null and b/doc/mallard/gda-data/interfaces-uml.png differ