Site reorganization

[alexey-igrychev]

• Add Documentation section.
• Move Quickstart, Security and Reference to Documentation.
• Make Documentation/How it works from sections of the Home page.
• Remove all sections except problems and benefits from the Home page.
• Fix styles on the Home page.
• Integrate How it works, Quickstart and Security into Documentation section.

[alexey-igrychev]

Closing as stale: no activity or demand since it was filed, and it is not on the roadmap. If you need this, comment here and we will reopen it with a concrete use case.