Compatibility with Vue 3

Thanks for providing `vue-selectize`, I find the component very interesting.
I tried to follow the steps given in [Getting started](https://vue-selectize.vilanculo.me/guide/#installation) section of the documentation, but couldn't make it work. Does this component work with Vue version 3? Is this project actively maintained?

Start with the Getting started installation section linked in the issue and determine whether the component supports Vue 3. Done means establishing the supported Vue version and documenting or addressing the compatibility outcome; no source files or tests are identified in the issue.

Written by the indexing model from the issue text.