Allow USWDS Compile to have option of Sass or Sass embedded

[brunerae]

Relates to: #20 and #28

Create a new setting that lets you compile Sass with plain Sass or Sass embedded.

[thisisdano]

@mejiaj I'm disinclined to pursue this solution, as it seems like an unnecessary complexity, but I'd like your opinion on the severity of the problem this would solve and the complexity of the solution.

[smustgrave]

ran into this error again for ddev same issue.

[smustgrave]

Updating sass-embeded fixed it https://github.com/uswds/uswds-compile/pull/47/files

[mejiaj]

@thisisdano agreed. Sass embedded is meant to support legacy and new API. This doesn't seem like an issue any more.