docs: Add ICP JavaScript SDK to showcase (#611)

Signed-off-by: David Dal Busco <david.dalbusco@outlook.com>

Author: peterpeterparker

showcase.json

@@ -125,5 +125,12 @@
     "description": "Bitcoin meets Africa, everywhere, for everyone",
     "img": "https://www.afritokeni.com/afriTokeni.svg",
     "twitter": "afritokeni"
+  },
+  {
+    "title": "ICP JavaScript SDK Docs",
+    "url": "https://javascript.icp.build",
+    "description": "Official documentation for building on the Internet Computer with JavaScript.",
+    "img": "/showcase/js-icp-build.webp",
+    "twitter": "DFINITYDev"
   }
 ]