Document how to use the same icon from different sets

I think @jeitneir’s excellent comment on #77 about how to import an icon with an alias should be incorporated into the documentation. Perhaps I’m just stupid, but it took me a while to work out how to use check circle from both the solid and the regular set.

to be clear, this is a copy of @jeitneir’s example from #77

import {
  faEdit
} from '@fortawesome/fontawesome-free-solid'

import {
  faEdit as faEditRegular
} from '@fortawesome/fontawesome-free-regular'

fontawesome.library.add(
  faEdit,
  faEditRegular
)

[NJM8]

I’d like to add to this for those who find it, and as a suggestion in the documentation, when you use the same icons from different libraries and you alias the import, you do not use the alias in your icon usage, you still use the regular name.

import { faStar } from "@fortawesome/pro-regular-svg-icons/faStar";
import { faStar as faStarSolid } from "@fortawesome/pro-solid-svg-icons/faStar";

library.add(
  faStar,
  faStarSolid
);

          <font-awesome-icon 
            :icon="['fas', 'star']"/>
          <font-awesome-icon 
            :icon="['far', 'star']"/>

[Adavo]

This is gold. Please add this to the doc ASAP. I cannot recover the time stupidly spent on finding how to do so but it can save next one’s time 😃