Feature request: multi-line tips.

It would be great if tips or warns can be writen in multiple lines, like blockquotes. Such as:

```markdown
!> Important things:
!> 1. Foo
!> 2. Bar

?> Tips:
?> - Foo
?> - Bar
```

At this time, if I write like this, I will got some "!>"s or "?>"s displayed.