Installation docs: is import required or what?

Reading the docs, it was not clear to me how to get this work with ChartJS4 in my context of a web app (Vue or React).

Through trial-and-error, I discovered I simply needed to add:

```
import ChartDeferred from 'chartjs-plugin-deferred'
ChartJS.register(, ChartDeferred)
```

Maybe I missed it or I'm overlooking something obvious, this doesn't seem to be mentioned anywhere in the main git readme or the npm page for this library.