message: shell: update brief
diff: @@ -70,6 +70,8 @@ public:
  *
  * If shell_message.data string have not trailing '\n' symbol - it will be added.
  *
  + * If response data looks like not completed try to increase timeout value in request.
  + *
  * @param shell_message Shell `struct`.
  */
  Shell::Result shell_command(ShellMessage shell_message);
  