Add homepage key to package.json

Author: Mikolaj Smolenski

package.json

@@ -2,6 +2,7 @@
   "name": "mdb-ui-kit",
   "version": "3.3.0",
   "main": "js/mdb.min.js",
+  "homepage": "https://mdbootstrap.com/docs/standard/",
   "repository": "https://github.com/mdbootstrap/mdb-ui-kit.git",
   "author": "MDBootstrap",
   "license": "MIT"