Module documentation: switch to Markdown

src/modules/mavlink/mavlink_main.cpp

@@ -2703,19 +2703,23 @@ static void usage()
 
 	PRINT_MODULE_DESCRIPTION(
 		R"DESCR_STR(
+### Description
 This module implements the MAVLink protocol, which can be used on a Serial link or UDP network connection.
 It communicates with the system via uORB: some messages are directly handled in the module (eg. mission
 protocol), others are published via uORB (eg. vehicle_command).
 
 Streams are used to send periodic messages with a specific rate, such as the vehicle attitude.
 When starting the mavlink instance, a mode can be specified, which defines the set of enabled streams with their rates.
-For a running instance, streams can be configured via 'mavlink stream' command.
+For a running instance, streams can be configured via `mavlink stream` command.
 
 There can be multiple independent instances of the module, each connected to one serial device or network port.
 
-The implementation uses 2 threads, a sending and a receiving thread.
+### Implementation
+The implementation uses 2 threads, a sending and a receiving thread. The sender runs at a fixed rate and dynamically
+reduces the rates of the streams if the combined bandwidth is higher than the configured rate (`-r`) or the
+physical link becomes saturated. This can be checked with `mavlink status`, see if `rate mult` is less than 1.
 
-Example usage:
+### Examples
 Start mavlink on ttyS1 serial with baudrate 921600 and maximum sending rate of 80kB/s:
 $ mavlink start -d /dev/ttyS1 -b 921600 -m onboard -r 80000