Describe overriding built-in component defaults

[yandodov]

Setting defaults for custom components is documented here, but changing built-in component defaults isn't:

import { ScrollTo } from "oblik/components/scroll-to";
import { easeOutQuint } from "oblik/utils/easings";

ScrollTo.defaults.easing = easeOutQuint;
ScrollTo.defaults.duration = 800;