setting up test cases for additional import rule examples

[thescientist13]

Related Issue

Found some gaps in our @import rule handling

• upgrade Greenwood v0.27.0 greenwood-template-blog#6
• upgrade Greenwood v0.27.0 greenwood-getting-started#66
• upgrade Greenwood v0.27.0 projectevergreen.github.io#92

/* expected */
@tailwind base;
@tailwind components;
@tailwind utilities;

/* actual */
@tailwind base}
@tailwind components}
@tailwind utilities}

/* not support at all!! */
@import url('https://fonts.googleapis.com/css?family=Raleway&display=swap');

Summary of Changes

N / A

TODO

1. Add support for remote @import url
2. Add support for "plain" at rule, per Tailwind style
3. Add test cases

[thescientist13]

duplicated by #999