Remove GitHub line from homepage

Removing GitHub mention from homepage. Happy to chat more but I think it makes us look weak and defensive. We should win in better product and marketing without having this line on the homepage of website. Would prefer we made it a two horse race in the media (like we've been seeing) and via our customers instead of saying this. Have heard this feedback from multiple people and I agree. Will work on our competitive analysis for sales enablement and include all of the info on the page there.