Awesome plugin!
It would be good to add some examples on how to go about theming this plugin, as it doesn't seem so straight forward. I noticed in the change-log, theming for this plugin is undergoing a redesign, but for in the meantime i think adding a repo link to the custom calendar at the bottom of https://vcalendar.io/#birthdate would be cool.
Maybe even a basic explanation of how to use theme-styles under the guide.
This file https://github.com/nathanreyes/v-calendar/blob/next/src/utils/defaults/theme.js is what you need :)