Implement playground area for pure HTML content development

[david-poindexter]

Is your feature request related to a problem?

Due to the way Tailwind CSS works with the Just-In-Time (JIT) compiler, content for a site will need to be parsed for the inclusion of necessary styles.

Describe the solution you'd like

It would be nice to have a "playground" or "content staging" area to work on HTML standalone within the theme development environment.

Describe alternatives you've considered

None at this time.

Additional context

This may be a separate npm script with a local live-reload dev server, or maybe it can leverage the existing browser-sync with the gulp serve. This is to be determined.