Add keywords

Author: ivankravets

platform.json

@@ -2,6 +2,7 @@
     "name": "gd32v",
     "title": "GigaDevice GD32V",
     "version": "0.0.1",
+    "keywords": "risc-v, gd32v, sipeed, longan, arduino",
     "description": "The GigaDevice GD32V device is a 32-bit general-purpose microcontroller based on the RISC-V core with an impressive balance of processing power, reduced power consumption and peripheral set.",
     "url": "https://www.gigadevice.com/products/microcontrollers/gd32/risc-v/",
     "homepage": "http://platformio.org/platforms/gd32v",