refactor: Improve code readability and performance in app.py

app.py

@@ -17,10 +17,18 @@ st.title("Light-mixing Control Panel")
 # Description and context
 st.markdown(
     """
-This application accesses a public test demo located in Toronto, ON, Canada (as of 2024-07-27). 
-For more context, you can refer to this [Colab notebook](https://colab.research.google.com/github/sparks-baird/self-driving-lab-demo/blob/main/notebooks/4.2-paho-mqtt-colab-sdl-demo-test.ipynb) 
-and the [self-driving-lab-demo project](https://github.com/sparks-baird/self-driving-lab-demo).
-You may also be interested in the Acceleration Consortium's ["Hello World" microcourse](https://ac-microcourses.readthedocs.io/en/latest/courses/hello-world/index.html) for self-driving labs.
+This application accesses a public test demo of a "light-mixer" located in
+Toronto, ON, Canada (as of 2024-07-27). Send RGB commands to a NeoPixel LED and
+visualize the spectral sensor data from an AS7341 sensor.
+
+For more context, you
+can refer to this [Colab
+notebook](https://colab.research.google.com/github/sparks-baird/self-driving-lab-demo/blob/main/notebooks/4.2-paho-mqtt-colab-sdl-demo-test.ipynb)
+and the [self-driving-lab-demo
+project](https://github.com/sparks-baird/self-driving-lab-demo). You may also be
+interested in the Acceleration Consortium's ["Hello World"
+microcourse](https://ac-microcourses.readthedocs.io/en/latest/courses/hello-world/index.html)
+for self-driving labs.
 """
 )