fix: 🚑 fix wrong main property

why

package.json

@@ -2,7 +2,7 @@
 	"name": "@pumpn/babel-preset",
 	"version": "0.7.0",
 	"description": "standard babel preset for pumpn code projects",
-	"main": "index.json",
+	"main": "index.js",
 	"repository": "https://github.com/pumpncode/babel-preset",
 	"author": "Nano Miratus <nanomiratus@gmail.com>",
 	"license": "MIT",