chore: fix the description of package.json

Author: yusukebe

jest.config.js renamed to jest.config.cjs

@@ -1,9 +1,10 @@
 {
   "name": "@picojs/pico",
-  "description": "Ultra-tiny web framework for Cloudflare Workers and Deno",
+  "description": "Ultra-tiny router for Cloudflare Workers and Deno",
   "version": "0.3.0",
   "types": "dist/index.d.ts",
   "module": "dist/index.js",
+  "type": "module",
   "files": [
     "dist"
   ],
@@ -59,4 +60,4 @@
   "engines": {
     "node": ">=16.0.0"
   }
-}
+}