boards/arduino-mkrwan1300: update doc about flash and stdio

boards/arduino-mkrwan1300/doc.txt

@@ -1,37 +1,37 @@
 /**
- * @defgroup    boards_arduino-mkrwan1300 Arduino MKR WAN 1300
- * @ingroup     boards
- * @brief       Support for the Arduino MKR WAN 1300 board.
- *
- * ### General information
- *
- * The [Arduino MKR WAN 1300](https://store.arduino.cc/mkr-wan-1300) board is
- * a learning and development board that provides LoRa connectivity and is
- * powered by an Atmel SAMD21 microcontroller.
- *
- * ### Pinout
- *
- * <img src="https://www.arduino.cc/en/uploads/Main/MKR1000_pinout.png"
- *      alt="Arduino MKR WAN 1300 pinout" style="height:800px;"/>
- *
- * ### Flash the board
- *
- * 1. Put the board in bootloader mode by double tapping the reset button.<br/>
- *    When the board is in bootloader mode, the user led (amber) oscillates
- *    smoothly.
- *
- *
- * 2. Use `BOARD=arduino-mkrwan1300` with the `make` command.<br/>
- *    Example with `hello-world` application:
- * ```
- *      make BOARD=arduino-mkrwan1300 -C examples/hello-world flash
- * ```
- *
- * @warning Unplug the board from the anti-static protective foam before
- *          starting to use it otherwise it may not work as expected.
- *
- * ### Accessing STDIO via UART
- *
- * To access the STDIO of RIOT, a FTDI to USB converted needs to be plugged to
- * the RX/TX pins on the board.
+@defgroup    boards_arduino-mkrwan1300 Arduino MKR WAN 1300
+@ingroup     boards
+@brief       Support for the Arduino MKR WAN 1300 board.
+
+### General information
+
+The [Arduino MKR WAN 1300](https://store.arduino.cc/mkr-wan-1300) board is
+a learning and development board that provides LoRa connectivity and is
+powered by an Atmel SAMD21 microcontroller.
+
+### Pinout
+
+<img src="https://www.arduino.cc/en/uploads/Main/MKR1000_pinout.png"
+     alt="Arduino MKR WAN 1300 pinout" style="height:800px;"/>
+
+### Flash the board
+
+Use `BOARD=arduino-mkrgsm1400` with the `make` command.<br/>
+Example with `hello-world` application:
+```
+     make BOARD=arduino-mkrgsm1400 -C examples/hello-world flash
+```
+
+@note     If the application crashes, automatic reflashing via USB, as explained
+          above won't be possible. In this case, the board must be set in
+          bootloader mode by double tapping the reset button before running the
+          flash command.
+
+### Accessing STDIO via UART
+
+STDIO of RIOT is directly available over the USB port.
+
+The `TERM_DELAY` environment variable can be used to add a delay (in second)
+before opening the serial terminal. The default value is 2s which should be
+enough in most of the situation.
  */