add simulation

Ad the simulation launcher description

simulation/app.md

+---
+layout: default
+title: Overview
+---
+
+
+# APP
+
+Built on top of the Modelio tool, the INTO-CPS Application is the front-end of the INTO-CPS tool chain.
+Embedded in the Browser and Editor modules,  the following screenshot shows how it looks.
+
+![1]
+
+Taking as input a configuration generated from an INTO-CPS Model, the INTO-CPS Application allows you to complete, 
+thanks to a specific editor, the specification of the co-simulation orchestrated by the COE.
+
+This editor is composed of four tabs:
+
+- FMU Tab, listing the FMUs used for the simulation.
+- Connection Tab, showing the specified connections.
+- Parameter Tab, where parameter values are initialized.
+- Algorithm Tab, for specifying the algorithm type and its different values. 
+
+Note that the FMU and Connection tabs can not be modified from this editor (they come from the model generation).
+
+![2]
+
+
+Once the co-simulation configuration has been fully specified, it is possible to run the co-simulation. 
+At the end of the simulation activity, a folder will be created inside the results folder, containing the co-simulation configuration and the results, in CSV format.
+
+![3]
+
+[1]: app-general-aspect.png
+
+[2]: app-fmus.png
+
+[3]: app-result.png
+