feat: add package.json exports prop

package.json

@@ -5,6 +5,7 @@
   "description": "Library with various utilities for userscripts - register listeners for when CSS selectors exist, intercept events, create persistent & synchronous data stores, modify the DOM more easily and more",
   "main": "dist/index.js",
   "module": "dist/index.mjs",
+  "exports": "./lib/index.ts",
   "types": "dist/lib/index.d.ts",
   "scripts": {
     "lint": "tsc --noEmit && eslint .",