Add TypeScript support

[kinow]

No description provided.

[kinow]

https://github.blog/changelog/2020-12-16-npm-displays-packages-with-bundled-typescript-declarations/

[kinow]

vuejs/vue-cli#5552

[kinow]

Had another go today, this time trying to move things to Vue 3. Got most of the code updated to TS, also added the entries I think we needed to have the .d.ts included.

Alas, the demo application wouldn't start right, always failing with the same error

[Vue warn]: HMR API usage is out of date.
Please upgrade vue-loader/vite/rollup-plugin-vue or other relevant depdendency that handles Vue SFC compilation.

I think it will have to wait until I start upgrading the app I'm working on at $work to Vue 3. That app uses the code from this library, so I will have more time to learn how to update and package the library. Sorry if anyone is waiting for this to use the library with TypeScript or Vue3 😞

[kinow]

Finished moving it to Vue 3 and Vite. Hopefully this task will be easier now to implement (later, as I ran out of bandwidth for this project for now). Pull requests, suggestions, are welcome!