[Site] Add "Icons" menu item

[smnandre]

• Add Icon menu item in nav
• Remove dead code
• Add test
• Fix footer links

[smnandre]

Oops.. some override #1672 sorry :)

[smnandre]

I inserted changes from #1672

[WebMamba]

Hey @smnandre this is detail, but I think the new at the top of the icon nav item should be more visible. Maybe we can make it bigger? Or add a background around? In mobile, the new is far from the world Icon so we don't get that the new is for icon. See some screenshots here:

[smnandre]

Hey @smnandre this is detail, but I think the new at the top of the icon na [...]

Fixed by ... removing it as it has not the same goal on desktop where we want from the homepage to show it.. In the menu were someone already look at this different pages it has less use i think.

[WebMamba]

Thanks @smnandre it looks good!

There a few bugs in mobile that we should fix in other PRs. I gonna do an issue for it 😁

[javiereguiluz]

Let's merge this to give Icons more exposure ... and we can tweak it later if we don't like anything. Thanks Simon! and thanks Matheo for the review.