Add option for treating `<caption>` in table as a table title above the table

Created by: cdmo

Before opening:

I read https://github.com/twbs/bootstrap/issues/28499 and would like to request an additional configuration instead of a reversion.

I think it's pretty common to want to have a table's caption come before the table, see Example 1 from Web Accessibility Tutorials' Caption & Summary.

It'd be nice to be able to apply a class to a caption and have it override default behavior like:

    padding-top: .75rem;
    padding-bottom: .75rem;
    text-align: left;
    caption-side: top;
    /** insert additional properties to mimick a, say, h2
}