Align 3.0.0

• Breaking Change: The Alignment used in pin() method now works slightly differently by default for the pre-defined .trailing, .leading, .bottom, and .top alignments. Previously, .leading alignment would pin to the view to the .leading horizontal guide and .fill the view vertically. In Align 3.0, it centers the view vertically instead.
• Add new documentation created using DocC
• Increase the minimum required Xcode version to 13.3
• Increase the minimum supported platforms to iOS 12.0 / tvOS 12.0 / macOS 10.14
• Rename LayoutAnchors/base to LayoutAnchors/item
• Move Alignment to AnchorCollectionEdges/Alignment
• Fix typos