Update samples/tone_doremi/README.rst

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: soburi

samples/tone_doremi/README.rst

@@ -14,8 +14,8 @@ Building and Running
 
 Build and flash tone_doremi sample as follows,
 
-```sh
-$> west build -p -b arduino_nano_33_ble samples/tone_doremi/
+.. code-block:: sh
 
-$> west flash --bossac=/home/$USER/.arduino15/packages/arduino/tools/bossac/1.9.1-arduino2/bossac
-```
+   $> west build -p -b arduino_nano_33_ble samples/tone_doremi/
+
+   $> west flash --bossac=/home/$USER/.arduino15/packages/arduino/tools/bossac/1.9.1-arduino2/bossac