0.4.0

Highlights

• Simplifies HTMLPreview so previews are written as #Preview { HTMLPreview { ... } }.
• Keeps preview titles in SwiftUI #Preview instead of duplicating title state in HTMLPreview.
• Updates README and DocC with a flat, copyable release dashboard preview sample.
• Keeps preview renderer tests aligned with the simplified API.

Verification

• xcodebuild test -scheme swift-html-Package -destination platform=macOS passed.