Make external numeric resources dynamic

[bechir]

This section of page is actually static

I suggest us to add a model to manage this section.
So here are a few things to do:

• Add entity with:
• A title for the resource
• A subtitle as shown in the figure
• A link to the resource
• And eventually an image (optional ?)
• Add (in the backend) a CRUD for theses resources
• And in base.html.twig, before the footer we render controller that fetch the resources in as below: {{ render(controller('App\\Controller\\ResourceController::getItems')) }}