fix bad link on stats page
fix the pair program with team viewer view
make tweet action open in new tab and add image for twitter card
attempt to fix twitter_card
remove redundant meta tag
update sitemap
hardcode paths into sitemap for now - we can optimize this later but it's too important to wait.
fix typos on sitemap
adjust meta description for twitter
make meta tag updates based on Mark Howard recommendations
add open source ribon to landing page
update video link
add omitted link to challenges.json