Changed arch linux from h2 to h3

I updated the install instructions (snap, scoop, chocolatey) and added the ones where Gutenberg already got renamed to Zola also to the top of the document.

Should yaourt be replaced by one of the other aur-helpers (pikaur, yay,...) as the development for it is stalled/discontinued for quite some time now although it is still working?

Scoop: https://github.com/lukesampson/scoop/blob/master/bucket/zola.json
Chocolatey: https://chocolatey.org/packages/zola
Snap: https://snapcraft.io/zola

It's either Arch Linux or archlinux but never Archlinux or ArchLinux.

* Finishing up site

* Make site a bit responsive

* Fix menu responsiveness

* Remove Fira Sans and revamp a bit text

* Update list of syntax and change output of syntax

* Add Rust mention

* Some doc tweaks

* Correct capitalization for GitHub

Correct capitalization for GitHub

* Some CSS tweaks

* More css tweaks + favicon

* Add link to my site

And some tweaks as I write the docs