add legacy entry points to package.json

Author: devgioele

package.json

@@ -11,6 +11,9 @@
     "readme.md",
     "dist/**/*"
   ],
+  "main": "dist/cjs/index.js",
+  "module": "dist/esm/index.js",
+  "types": "dist/types/index.d.ts",
   "exports": {
     ".": {
       "types": "./dist/types/index.d.ts",