Add shortcode button for easily adding the shortcode wrapper and selecting options

[jtsternberg]

Specifically thinking of adding https://github.com/jtsternberg/Shortcode_Button to easily surface the short-code options from within the editor via a button/modal combo.

[Viper007Bond]

Hmm, it probably couldn't hurt. I'd want it to always use [code] and then prompt for the lang parameter though (I kind of want to deprecate the language-specific shortcodes like [php]). I also think it'd be option bloat to have the dialog box contain all of those parameters. I think prompting for language and light (i.e. line numbers or not) only probably makes the most sense.

I'm also not usually a big fan of using libraries for fairly simple stuff like this but it probably does make sense in this case to use one.