Adds top-level types to package.json

Author: aaronzi

package.json

@@ -4,6 +4,7 @@
   "description": "BaSyx TypeScript SDK for developing applications and components for the Asset Administration Shell (AAS)",
   "type": "module",
   "main": "bundle/index.js",
+  "types": "dist/index.d.ts",
   "exports": {
     ".": {
       "import": "./bundle/index.js",