message: Add summary_large_image to block meta tags
diff: @@ -4,6 +4,7 @@ meta( property='og:title' content="Are.na / #{block.get('title')}" )
  meta( property='og:url' content="https://www.are.na/block/#{block.id}" )
  if block.has('image')
  + meta( name="twitter:card", content="summary_large_image" )
  meta( name='twitter:image1', content= block.get('image').display.url )
  meta( property='og:image' content= block.get('image').display.url )
  