Meaningful textarea whitespace removed

[dsingleton]

Hi!

First, thanks for the lib, it's super useful 👍

I've spotted a bug with the handling of <textarea> content whitespace, where it's removed by prettyPrint:

require('html').prettyPrint('<textarea>     hello    </textarea>')

Results in:

<textarea>hello</textarea>

The whitespace inside a <textarea> is semantic and removing it changes the meaning of the <textarea>.

[robinwhittleton]

I made a PR for this: https://github.com/maxogden/commonjs-html-prettyprinter/pull/16