fix: add package.json to package exports (#394)

Author: techniq

package.json

@@ -13,7 +13,8 @@
         ".": {
             "types": "./index.d.ts",
             "default": "./plugin.js"
-        }
+        },
+        "./package.json": "./package.json"
     },
     "scripts": {
         "build": "rollup -c",