Fix SEO google search card preview favicon

[joepio]

Currently we don't see a favicon in the search preview (even though there is a rel="icon" set in the head), probably because the current resolution is not a multiple of 48, like 192x192.

Some options:

• I could try 480x480. Still high res where needed.
• SVG, but is not supported on various browsers (e.g. safari)
• Smaller or .ico variant? Seems outdated and unnecessary

[joepio]

Tried a 480x480

[joepio]

Hmm, still shows the globe icon in google instead of the favicon.

[Pato-desu]

I see it working well on Google and every other engine that I tried except Bing