Clarify Blueprint on landing page

wtf is blueprint?

right now it's very intimidating, and it needs to be easier to understand, without sacrificing a lot of clarity.

Start at the landing page and review how Blueprint is currently introduced to a first-time visitor. Clarify what Blueprint is and why it exists without sacrificing clarity; the landing page should be understandable rather than intimidating when this is done.

Written by the indexing model from the issue text.