Add API details for c#

Author: Juhi Shah

specs/WebRtcPortConfiguration.md

@@ -151,8 +151,79 @@ interface ICoreWebView2StagingEnvironmentOptions10
 }
 ```
 
+## C#
+
+```csharp
+/// <summary>
+/// Specifies the WebRTC protocol type for port range configuration.
+/// </summary>
+public enum CoreWebView2WebRtcProtocolKind
+{
+    /// <summary>
+    /// UDP protocol for WebRTC media and ICE candidates.
+    /// </summary>
+    Udp = 0,
+    /// <summary>
+    /// TCP protocol for WebRTC media and ICE candidates (future support).
+    /// </summary>
+    Tcp = 1,
+}
+
+/// <summary>
+/// WebRTC port configuration interface for managing WebRTC port range configuration.
+/// This interface provides methods to configure and retrieve custom port ranges
+/// that WebRTC will use for ICE candidates and media connections across different protocols.
+/// </summary>
+public interface ICoreWebView2WebRtcPortConfiguration
+{
+    /// <summary>
+    /// The SetPortRange method allows you to set a custom port range for WebRTC to use
+    /// for a specific protocol type.
+    /// This method allows configuring a specific port range that WebRTC will use
+    /// for ICE candidates and media connections for the specified protocol.
+    /// 
+    /// protocol specifies the WebRTC protocol type (UDP, TCP, etc.).
+    /// minPort and maxPort must be in the range 1025-65535 (inclusive).
+    /// minPort must be less than or equal to maxPort.
+    /// If minPort equals maxPort, it represents a single port.
+    /// 
+    /// Calling this method will replace any previously configured port range for the specified protocol.
+    /// </summary>
+    /// <param name="protocol">The WebRTC protocol type</param>
+    /// <param name="minPort">Minimum port in the range (1025-65535)</param>
+    /// <param name="maxPort">Maximum port in the range (1025-65535)</param>
+    void SetPortRange(CoreWebView2WebRtcProtocolKind protocol, uint minPort, uint maxPort);
+
+    /// <summary>
+    /// The GetPortRange method gets the currently configured port range for a specific protocol.
+    /// Returns true if a custom port range is configured for the specified protocol, 
+    /// with the range values in out parameters.
+    /// Returns false if no custom range is set for the protocol (using default dynamic allocation), 
+    /// in which case the out parameter values should be ignored.
+    /// </summary>
+    /// <param name="protocol">The WebRTC protocol type</param>
+    /// <param name="minPort">Output parameter for minimum port in the range</param>
+    /// <param name="maxPort">Output parameter for maximum port in the range</param>
+    /// <returns>True if custom range is configured, false if using default allocation</returns>
+    bool GetPortRange(CoreWebView2WebRtcProtocolKind protocol, out uint minPort, out uint maxPort);
+}
+
+/// <summary>
+/// Additional options used to create WebView2 Environment to manage WebRTC port range configuration.
+/// </summary>
+public interface ICoreWebView2EnvironmentOptions
+{
+    /// <summary>
+    /// Gets the WebRTC port configuration object for configuring custom port ranges.
+    /// This configuration can be used to set and retrieve port range configuration
+    /// that WebRTC will use for ICE candidates and media connections.
+    /// </summary>
+    ICoreWebView2WebRtcPortConfiguration WebRtcPortConfiguration { get; }
+}
+```
 
 # Appendix
+
 Validation rules: Ports must be within 1025–65535. Calls with invalid ranges return E_INVALIDARG.
 Default behavior: If no range is configured, WebRTC uses the OS ephemeral port range.
 Thread safety: Configuration must be completed before the environment is created.