add dependencies

docs/src/index.md

@@ -1,5 +1,7 @@
 # Calculus of variations
 
+## Introduction
+
 Let consider $\mathcal{I}$ an open interval of $\mathbb{R}$, $\Omega$ an open set of $\mathbb{R}^n$ and 
 a continuous application 
 
@@ -55,4 +57,13 @@ as
 with a slight abuse of notations since from the optimal control point of view, the cost depends
 generally on the state $x$ and the control $u$.
 
-You may find an example of such a problem [here](@ref catenoid).
+You may find an example of such a problem [here](@ref catenoid).
+
+## Dependencies
+
+All the numerical simulations to generate this documentation are performed with the following packages.
+
+```@example
+using Pkg
+Pkg.status()
+```