Update file README.md

To build the application, run the following command:

```shell

cd motor

west build -b $BOARD motor

cd mambo

west build -b robomaster_board_c samples\motor\dji_m3508_demo

```

where `$BOARD` is the target board. Here you can use `robomaster_board_c`

`$BOARD` is the target board. Here you can use `robomaster_board_c`

A sample debug configuration is also provided. To apply it, run the following

command:

```shell

west build -b $BOARD blinky -- -DOVERLAY_CONFIG=debug.conf

west build -b $BOARD samples\motor\dji_m3508_demo

```

Once you have built the application, run the following command to flash it:

```shell

west flash

```

默认为stlink, 如果使用cmsis-dap请加上`--runner openocd`, Jlink则为`--runner jlink`

默认为cmsis-dap, 如果使用stlink请加上`--runner stlink`, Jlink则为`--runner jlink`

If everything goes well, the LED on the board should be blinking

Then you can have your motors running!