chore(showcase): Add Zona Digital to Gatsby Showcase (#23980)

Co-authored-by: Capela <[email protected]>
Co-authored-by: Matt Kane <[email protected]>

docs/sites.yml

@@ -10544,6 +10544,20 @@
   built_by: Sadharani Music Works
   built_by_url: https://www.sadharani.com
   featured: false
+- title: Zona Digital
+  url: https://zonadigital.pt
+  main_url: https://zonadigital.pt
+  description: >
+    We work with startups and small businesses building effective strategies through digital platforms. Based in Porto, Portugal.
+  categories:
+    - Web Development
+    - Programming
+    - Technology
+    - Design
+    - Business
+  built_by: Zona Digital
+  built_by_url: https://zonadigital.pt
+  featured: false
 - title: Ofri Lifshitz Design
   url: https://www.ofrilifshitz.com
   main_url: https://www.ofrilifshitz.com