Clarify packet peer `max_buffer_po2` in ProjectSettings documentation

This closes https://github.com/godotengine/godot-docs/issues/4364.

(cherry picked from commit c475b1fd0b1f8a74b535e123f39c03bf4a2443d3)

doc/classes/ProjectSettings.xml

@@ -856,7 +856,7 @@
 			Maximum number of warnings allowed to be sent as output from the debugger. Over this value, content is dropped. This helps not to stall the debugger connection.
 		</member>
 		<member name="network/limits/packet_peer_stream/max_buffer_po2" type="int" setter="" getter="" default="16">
-			Default size of packet peer stream for deserializing Godot data. Over this size, data is dropped.
+			Default size of packet peer stream for deserializing Godot data (in bytes, specified as a power of two). The default value [code]16[/code] is equal to 65,536 bytes. Over this size, data is dropped.
 		</member>
 		<member name="network/limits/tcp/connect_timeout_seconds" type="int" setter="" getter="" default="30">
 			Timeout (in seconds) for connection attempts using TCP.