Update copy on homepage
Update copy on homepage

@jbpros @romaingweb I've juggled things around a bit. I've put the
benefits up top on their own, and moved the BDD graphic to go next to
the paragraphs of text which basically describe the BDD process, so make
more sense there.

So how we have *why* (benefits) first, followed by *how* (BDD) second. I
think that makes more sense.

It would be great if you could make the benefits section look better. An
infographic style thing would be amazing, but just sorting the
typography layout for now would do!

cucumber/website,cucumber/website,cucumber/website