Homepage UI Overhaul

[almosnow]

Following our small UX meetup, where we gathered feedback from new serratus users, the following issue surfaced:

• The homepage could be redesigned to be more succinct and clear, in a way that new users know what it shown and where could they find specific functionality. Right now, this is not very clear and is a source of confusion.
• The Explorer and Toolkit tabs could be the same thing, a single page with all the tools that we provide, what they do and links to them.
• Improve documentation and add examples that reproduce results from the papers (or common scenarios).