fix: Add conditional exports to package.json (#815)

* fix: Add conditional exports to package.json

See https://nodejs.org/docs/latest-v22.x/api/packages.html#conditional-exports

* Update package.json

Author: lukescott

package.json

@@ -13,6 +13,11 @@
   "main": "dist/signature_pad.umd.js",
   "module": "dist/signature_pad.js",
   "types": "dist/types/signature_pad.d.ts",
+  "exports": {
+    "import": "./dist/signature_pad.js",
+    "require": "./dist/signature_pad.umd.js",
+    "default": "./dist/signature_pad.umd.js"
+  },
   "scripts": {
     "build": "yarn run lint && yarn run clean && rollup --config && yarn run emit-types && yarn run update-docs",
     "clean": "yarn run del dist",