Docs has outdated style for custom transition

[samselikoff]

Believe the docs has an example showing an older API for writing custom transitions:

https://ember-animation.github.io/liquid-fire/transition-map/choosing-transitions

// You can also provide an implementation instead of a name, though
// it's probably better to keep implementations in separate files. We
// talk more about transition implementations in the next section.
import { animate, stop } from "liquid-fire";
this.transition(
  this.withinRoute('foo'),
  this.use(function(oldView, insertNewView, opts) {
    stop(oldView);
    return animate(oldView, {opacity: 0}, opts)
      .then(insertNewView)
      .then(function(newView){
        return animate(newView, {opacity: [1, 0]}, opts);
      });
  })
);

If this is correct I can submit a PR

[ef4]

You're correct, thanks.