Support top-level site sections in site styling

[aiman]

We'd like the styling to support top-level sections of the site content, proposal is to make use of the space in the top-right corner, to the left of the search box.

Motivation is that LHS navigation has grown too large, a big wall of text. Depending on the goal of the user, most of the is not going to be relevant for them, so it creates friction to have to hunt for the right section.

A better way of organizing around the present content around users and their goals could be:

• Home
• Quick Start (install autonity CLI, fund accounts, CDP usage, delegate stake)
• Concepts (learn how protocol works, genesis config)
• Validators (install AGC, AOS, set up validator node)
• Developers (protocol contract docs, python SDK docs)

For the first iteration, we can put all current content in a single "Home" section, so that site structure is unchanged, and perhaps it can also be invisible initially.

Then we can coordinate with other contributors on restructing the site content in a subsequent change, to minimize git clashes.

[dweng0]

Quarto currently only supports one level of nesting in their navbar navigation based on this recent feature request issue. Pushing all the content into the menu as a flat menu would be too long (testing show that there is also no support for scrolling inside the menus).

So I recommend we add the navigation menus as you proposed, but hidden:

• Home
• Quick Start (install autonity CLI, fund accounts, CDP usage, delegate stake)
• Concepts (learn how protocol works, genesis config)
• Validators (install AGC, AOS, set up validator node)
• Developers (protocol contract docs, python SDK docs)

and then work with contributors to identify the relevant content for each menu and fill.