Update README.md

Author: emab

README.md

@@ -1,5 +1,13 @@
 # Valgen
 
-An app to help generate Barett Model diagrams.
+An app to help generate value model diagrams.
+
+Select from the provided values, or add your own which are saved locally for later use.
+
+Select `Show Preview` to see what you've added so far. If there are matching values between personal, current or desired values they are color coded in the tables.
+
+From the preview page, you can save the diagram by using the `Save` button.
+
+## Tech
 
 Built with Electron and React.