housekeeping: add homepage URL to package.json (#5652)

can be useful for folks looking at the file after they've downloaded it.

Author: coliff

package.json

@@ -2,6 +2,7 @@
   "name": "swagger-ui",
   "version": "3.23.11",
   "main": "dist/swagger-ui.js",
+  "homepage": "https://github.com/swagger-api/swagger-ui",
   "repository": "git@github.com:swagger-api/swagger-ui.git",
   "contributors": [
     "(in alphabetical order)",