Update paperclip.md (#511)
Update paperclip.md (#511)

* Update paperclip.md

Broken link to [metadata_attributes]

* Change link to docs for metadata attributes plugin

Co-authored-by: Hiren Mistry <8278acf7ba64778338d9f96b6654b31b354250de@chai-monsters.com>
janko-m/shrine,janko-m/shrine