Update the icon so it more closely resembles the in-game visual style
(and also so it compresses better) and update the screenshot since the
old one is the wrong size (FullHD instead of 358x406) and doesn't render
correctly in the documentation.
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
Signed-off-by: Johannes Wache <jbwa@posteo.de>
[daniel@redfelineninja.org.uk: Removed some couple of unwanted merge artifacts]
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
