Update all assets related to the previous naming.
I gave some asset a more generic name, so if the app's name chang again
we won't have to rename the logo.
Linked but not assets, meta title and description were updated.
Next.js favicon was replaced by the Equipes' one.
2 routers exists in Next.js, "app" router and "page" router.
The "app" router has a bug introduced in Next.js 13.4.14, which is
not fixed yet. For the moment we cannot use dynamic routes with
"app" router with an SPA. As advised by the Next.js team, we
migrated to the "pages" router.
