Add Raise Sherpas to sponsor section

[fe51]

Thanks to their recent support, we need to add "Raise Sherpas" to the section, "Qui nous soutient ?"

• Link to their website : https://www.raise-sherpas.co/

• Raise Sherpas's logo is available here : https://cdn.prod.website-files.com/66701ca362f594b05744fbe0/66701ca362f594b05744fcd7_RAISE_SHERPAS_HORIZONTAL_BLANC%25201-p-500.png
  => might be better to add on with color and I saw one on linkedin, not horizontal that might suits better with our website.

• Related description, in french : "Qui nous soutient humainement et financièrement via leur accélérateur philanthropique"

Reminder : to not forget to add an alternative Desc to the logo in the html ;)

Thanks a lot