Content: Improve the About > Logos page

[ryelle]

Copied from #meta-7710 Created by @jdevalk

Our logo page needs some work: https://wordpress.org/about/logos/

I think we should:

• Remove the “Graphics & Logo” h1 and make the “Official WordPress logo” (currently the h2) the h1
• Replace “Downloads” with “Logo files”
• Add SVG versions of all the files (WordPress logo svg is actually sought a lot)

Screenshot of proposed design changes

Oh and let's change the title to "Official WordPress logo" too.