fix: reexport default export of typescript module

[miegl]

This fixes the following when using the module with TS:

TS1192: Module '"node_modules/@vueform/multiselect/src/index"' has no default export.
[index.d.ts(1, 1): ]()'export *' does not re-export a default.

[stale]

Hi 👋 this issue has been automatically marked as stale 📌 because it has not had recent activity 😴. It will be closed if no further activity occurs.

[icithis]

Has this been resolved outside of this pull request, or is there another reason it hasn’t been merged?

[adamberecz]

Thanks, I appreciate it