[Concurrency] Improve new TaskLocal macro documentation

Author: ktoso

stdlib/public/Concurrency/TaskLocal.swift

@@ -17,7 +17,9 @@ import Swift
 // Macros are disabled when Swift is built without swift-syntax.
 #if $Macros && hasAttribute(attached)
 
-// TODO: docs
+/// Macro that introduces a ``TaskLocal-class`` binding.
+///
+/// - SeeAlso: ``TaskLocal-class``
 @available(SwiftStdlib 5.1, *)
 @attached(accessor)
 @attached(peer, names: prefixed(`$`))
@@ -26,22 +28,25 @@ public macro TaskLocal() =
 
 #endif
 
-/// Wrapper that defines a task-local value key.
+/// Wrapper type that defines a task-local value key.
 ///
 /// A task-local value is a value that can be bound and read in the context of a
-/// `Task`. It is implicitly carried with the task, and is accessible by any
-/// child tasks the task creates (such as TaskGroup or `async let` created tasks).
+/// ``Task``. It is implicitly carried with the task, and is accessible by any
+/// child tasks it creates (such as TaskGroup or `async let` created tasks).
 ///
 /// ### Task-local declarations
 ///
-/// Task locals must be declared as static properties (or global properties,
-/// once property wrappers support these), like this:
+/// Task locals must be declared as static properties or global properties, like this:
 ///
 ///     enum Example {
 ///         @TaskLocal
 ///         static let traceID: TraceID?
 ///     }
 ///
+///     // Global task local properties are supported since Swift 6.0:
+///     @TaskLocal
+///     var contextualNumber: Int = 12
+///
 /// ### Default values
 /// Reading a task local value when no value was bound to it results in returning
 /// its default value. For a task local declared as optional (such as e.g. `TraceID?`),
@@ -150,6 +155,8 @@ public macro TaskLocal() =
 ///         read() // traceID: nil
 ///       }
 ///     }
+///
+/// - SeeAlso: ``TaskLocal-macro``
 @available(SwiftStdlib 5.1, *)
 public final class TaskLocal<Value: Sendable>: Sendable, CustomStringConvertible {
   let defaultValue: Value