Add toast examples
This MR adds some examples for the toast component.
Note: gitlab-org/gitlab-ui!263 (merged) needs to be merged first in order for this to work.
Closes: gitlab-org/gitlab-ui#247 (closed)
Preview:
(toasts.md)
[[Example:toast-default]]
[[Example:toast-action]]
Edited by 🤖 GitLab Bot 🤖