Add test image to R2 entry

Author: kodster28

src/content/changelog/r2/2025-02-14-r2-super-slurper-faster-migrations.mdx

@@ -4,6 +4,7 @@ description: Super Slurper now transfers data from cloud object storage provider
 products:
   - r2
 date: 2025-02-14T19:00:00Z
+cover: ~/assets/images/r2/slurper-objects-over-time-border.png
 ---
 
 [Super Slurper](/r2/data-migration/super-slurper/) now transfers data from cloud object storage providers like AWS S3 and Google Cloud Storage to [Cloudflare R2](/r2/) up to 5x faster than it did before.