[docs] add images to illustrate comms in ptask profile
The commit adds the following:
- A new picture to illustrate how to read a ptask profile.
- Add a sentence in the doc to introduce the figure.
[A venir] Mise en place de quotas sur nos instances GitLab. Plus d'information sur : https://doc-si.inria.fr/pages/viewpage.action?pageId=129728565
[Coming soon] Quotas installation on our GitLab instances. More information: https://doc-si.inria.fr/pages/viewpage.action?pageId=129728565
The commit adds the following: