I'm using OS X, but I don't think that matters.
By default, both MacVim and [terminal] Vim handle auto-indentation of HTML 4.0 elements, but any HTML5 elements, such as
<footer>, don't trigger the auto-indentation. They're also not syntax-highlighted.
How can I add let Vim recognize HTML5 elements, or better yet, make Vim recognize any element instead of only pre-configured ones?