Update to redesigned site

[nijynot]

No description provided.

[lehnberg]

@nijynot good news - at yesterday's governance meeting, all were in favour of this design improvement! I think it's pretty much good to go, with some minor tweaks:

• some smaller formatting tweaks on the responsiveness, see here.
• We've noticed that we don't have a proper link to our security and vulnerability policy. Would be great if this actually could be linked through from the website as well, perhaps under Learn More and in the footer (under grin column left most)?
• Improve this website link (bottom right) seems to not be formatted with new design?
• "Learn more" from hamburger menu on small screen sizes link just through to docs. Can we handle that better somehow?

[nijynot]

@lehnberg Ok, should be fixed now. Also added some more links, "Friends of Grin" page is now more accessible. Just ping me if there's anything else to change or you think could be better!

[lehnberg]

Awesome @nijynot! Please can you resolve the merge conflicts (see here in the PR for details)? Reckon you basically need to rebase friends, index, and yeastplume.md as they all changed since you started working on the site.

Once that's sorted, I will merge it. :)

[nijynot]

Done. Ready to be merged.