Add documentation for configureAsyncHTTP2Pipeline

Author: aryan-25

Sources/NIOHTTP2/HTTP2PipelineHelpers.swift

@@ -927,6 +927,27 @@ extension ChannelPipeline.SynchronousOperations {
         )
     }
 
+    /// Configures a `ChannelPipeline` to speak HTTP/2 and sets up mapping functions so that it may be interacted with
+    /// from concurrent code. This variant includes a ``NIOHTTP2ServerConnectionManagementHandler`` argument, and links
+    /// its stream and frame delegates with ``NIOHTTP2Handler``.
+    ///
+    /// This operation **must** be called on the event loop.
+    ///
+    /// In general this is not entirely useful by itself, as HTTP/2 is a negotiated protocol. This helper does not
+    /// handle negotiation. Instead, this simply adds the handler required to speak HTTP/2 after negotiation has
+    /// completed, or when agreed by prior knowledge. Use this function to setup a HTTP/2 pipeline if you wish to use
+    /// async sequence abstractions over inbound and outbound streams, as it allows that pipeline to evolve without
+    /// breaking your code.
+    ///
+    /// - Parameters:
+    ///   - mode: The mode this pipeline will operate in, server or client.
+    ///   - connectionManager: A ``NIOHTTP2ServerConnectionManagementHandler`` instance to use alongised the
+    ///   ``NIOHTTP2Handler``.
+    ///   - configuration: The settings that will be used when establishing the connection and new streams.
+    ///   - streamInitializer: A closure that will be called whenever the remote peer initiates a new stream.
+    ///     The output of this closure is the element type of the returned multiplexer
+    /// - Returns: An `EventLoopFuture` containing the `AsyncStreamMultiplexer` inserted into this pipeline, which can
+    ///   be used to initiate new streams and iterate over inbound HTTP/2 stream channels.
     @inlinable
     @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
     public func configureAsyncHTTP2Pipeline<Output: Sendable>(