Fix the shell-prompt from the reconfigure part.

ros2/respeaker_mic_array.md

@@ -58,4 +58,5 @@ There's also another topic called `/status_led`, with this topic you can change
 You can also set various parameters via `dynamic_reconfigure` by running the following command in a new terminal.
 
 ```{.bash .shell-prompt}
-ros2 run rqt_reconfigure rqt_reconfigure
+ros2 run rqt_reconfigure rqt_reconfigure
+```