Redesign software documentation pages

[strogonoff]

The idea is to further move away from the original designs and offer more minimalistic documentation pages for software & specs.

Top bar should be less intrusive and hidden by default (accessible via a logo/icon), so that focus inside docs is put on internal navigation.

Might attach mock-ups later.

This third-party project implements some of the ideas I had in mind regarding cleaner layout. It also moves sidebar to the left, which I’m not a fan of but Ronald believes is more intuitive: https://pmarsceill.github.io/just-the-docs/docs/customization/