Lucerne 0.4.0

Unsigned build

This app is not code-signed with a Developer ID or notarized, so macOS
Gatekeeper will warn on first launch. To open it:

• Right-click (or Control-click) the app → Open → Open, or
• run xattr -dr com.apple.quarantine /Applications/Lucerne.app

What's Changed

• Floating palettes: app-global Typefaces + Styles in classic chrome by @L-K-M in #14
• Extensible, editable styles: document-driven stylesheet, Style Editor panel, and the global Style Library by @L-K-M in #15

Full Changelog: v0.3.0...v0.4.0