Move vendor URL to "homepage" field

Author: ivankravets

platform.json

@@ -2,8 +2,7 @@
   "name": "espressif32",
   "title": "Espressif 32",
   "description": "Espressif Systems is a privately held fabless semiconductor company. They provide wireless communications and Wi-Fi chips which are widely used in mobile devices and the Internet of Things applications.",
-  "url": "https://espressif.com/",
-  "homepage": "http://platformio.org/platforms/espressif32",
+  "homepage": "https://espressif.com/",
   "license": "Apache-2.0",
   "engines": {
     "platformio": "<5"