Pre-release: Eleventy v3.0.0-alpha.20

• Dependency updates, including Dev Server v2.0.4: https://github.com/11ty/eleventy-dev-server/releases/tag/v2.0.4
• Fix: missing logger when a transform returns an empty string
• Internals: adds enabled callback to HtmlTransformer

Minutiae

Full Changelog: v3.0.0-alpha.19...v3.0.0-alpha.20
Full Eleventy v3 Milestone (170 closed): https://github.com/11ty/eleventy/milestone/40?closed=1