Apply suggestion from @jemgillam

Author: jemgillam

src/pages/sponsor.mdx

@@ -92,7 +92,7 @@ YOU!**
     href="https://constructive.io/"
     business
   />
-  <Sponsor name="Seaber" />
+  <Sponsor name="Seaber" avatar="/images/sponsors/Seaber.png" />
 </Sponsors>
 <Sponsors level="supporters">
   <Sponsor name="HR-ON" business />