update readme

docs/index.rst

@@ -15,6 +15,9 @@ Welcome to Adjustin's documentation!
    src/user_guide.rst
    src/developer_guide.rst
 
+The Adjustin package is a julia package for model simulation, parameters estimation and sensitivity_analysis.
+The Adjustin applications repository contains example of how to use this package and with which folder organisation.
+
 
 .. topic:: Installation guide