New sponsor image (#444)

Author: jemgillam

src/pages/sponsor.mdx

@@ -91,6 +91,7 @@ YOU!**
   <Sponsor name="Ravio" avatar="/images/sponsors/Ravio.svg" business />
   <Sponsor name="prodready" />
   <Sponsor name="Locomote" avatar="/images/sponsors/locomote.svg" />
+  <Sponsor name="Outbank" avatar="/images/sponsors/outbank.png" />
 </Sponsors>
 <Sponsors level="supporters">
   <Sponsor name="HR-ON" business />