Add platform limitations section to man page.

man/mosquitto.8.xml

@@ -91,6 +91,17 @@
 		</para>
 	</refsect1>
 
+	<refsect1>
+		<title>Platform limitations</title>
+		<para>
+			Some versions of Windows have limitations on the number of
+			concurrent connections due to the Windows API being used. In
+			modern versions of Windows, e.g. Windows 10 or Windows Server
+			2019, this is approximately 8192 connections. In earlier
+			versions of Windows, this limit is 2048 connections.
+		</para>
+	</refsect1>
+
 	<refsect1>
 		<title>MQTT Support</title>
 		<para>Mosquitto supports MQTT v5.0, v3.1.1, and v3.1.</para>