Update Win32API.cs

Author: yaira2

src/Files.App/Utils/Shell/Win32API.cs

@@ -229,7 +229,9 @@ private class IconAndOverlayCacheEntry
 		private static readonly object _lock = new object();
 
 		/// <summary>
-		/// 
+		/// Returns an icon when a thumbnail isn't available or if getIconOnly is true
+		/// Returns an icon overlay when getOverlay is true
+		/// Returns a boolean indicating if the icon/thumbnail is cached
 		/// </summary>
 		/// <param name="path"></param>
 		/// <param name="thumbnailSize"></param>