New documentation landing page

[fhennig]

As a user visiting the landing page, I want to get a quick overview of the documentation content and quickly navigate to the information I want.

Currently, the top menu is basically the only entrypoint into the content.

The introductory text currently at the top of the landing page is probably more suited for a concepts/background/explanation page, or even for stackable.tech.

Current Idea

Some of the documentation I like uses tiles (see examples below, with tiles we can show people what we think is important, and write a sentence of description on the tile as well, to help first time users quickly find what they need.

Examples from other documentation sites

Docker

GitLab

Datahub

GitHub

[fhennig]

@lfrancke ping