v0.3.1: Support Less CSS

What's Changed

• Inline import by @nvh95 in #248
• Deprecate externalCss in 0.3.1 by @nvh95 in #175
• Polish readme and docs by @nvh95 in #250
• docs: Add try now and Open in Stackblitz button by @nvh95 in #251
• Support LESS by @nvh95 in #253

Full Changelog: v0.3.0...v0.3.1