DIFlowLayout 1.1.0

Adds DIFlowLayout(spacing:) to apply the same spacing between items and between rows.

• Adds SwiftUI rendering tests for uniform spacing, wrapping, and ideal sizing.
• Includes expanded coverage for layout sizing and wrapping behavior.
• Updates the README usage and installation examples.
• Updates CI to use actions/checkout@v5.

Validation: all 12 tests pass with swift test; GitHub CI passes for macOS tests and the iOS build.

Full changelog: v1.0.3...v1.1.0