Add documentation

Sources/SwiftUIMath/TypesettingStyle.swift

@@ -1,13 +1,17 @@
 import SwiftUI
 
 extension Math {
+  /// Controls how math is typeset (display vs inline text).
   public enum TypesettingStyle: Sendable {
+    /// Display style for standalone equations.
     case display
+    /// Text style for inline math.
     case text
   }
 }
 
 extension View {
+  /// Sets the typesetting style for ``Math`` views in this hierarchy.
   public func mathTypesettingStyle(_ typesettingStyle: Math.TypesettingStyle) -> some View {
     environment(\.mathTypesettingStyle, typesettingStyle)
   }