chore: Update HiveMQ host, username, and password inputs in app.py

app.py

@@ -1,6 +1,5 @@
 import json
 import queue
-import threading
 
 import paho.mqtt.client as mqtt
 import streamlit as st
@@ -8,9 +7,17 @@ import streamlit as st
 # Initialize Streamlit app
 st.title("RGB Command and Sensor Data Panel")
 
-# MQTT Configuration
-
+# Description and context
+st.markdown(
+    """
+This application accesses a public test demo situated 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 for self-driving labs](https://ac-microcourses.readthedocs.io/en/latest/courses/hello-world/index.html).
+"""
+)
 
+# MQTT Configuration
 HIVEMQ_HOST = st.text_input(
     "Enter your HiveMQ host:",
     "248cc294c37642359297f75b7b023374.s2.eu.hivemq.cloud",