message: docs: add description
diff: {
  "name": "@kintone/rest-api-client",
  "version": "0.0.1",
  - "description": "",
  + "description": "Kintone REST API client for JavaScript",
  "main": "lib/index.js",
  "module": "esm/index.js",
  "types": "lib/index.d.ts",
  