chore:remove useless field main

Author: wh131462

package.json

@@ -2,7 +2,6 @@
   "name": "leetcode-practice",
   "version": "1.0.2",
   "description": "A powerful practice platform for leetcode.Using any way you want to create questions.",
-  "main": "index.js",
   "type": "module",
   "publishConfig": {
     "registry": "https://registry.npmjs.org/"