Added basic usage documentation to app.py

app.py

@@ -1,4 +1,33 @@
 #! /Users/arianagiroux/Documents/Coding/owncast-obs-streamer/venv/bin/python3
+""" A simple flask app to provide a streamer UI for obs and owncast.
+
+Usage:
+    $ ./app.py
+    > * Serving Flask app 'app' (lazy loading)
+    > * Environment: production
+    > WARNING: This is a development server. Do not use it in a production deployment.
+    > Use a production WSGI server instead.
+    > * Debug mode: off
+    > * Running on http://127.0.0.1:5000 (Press CTRL+C to quit)
+
+    > Open 127.0.0.1:5000 in your local browser
+
+Note:
+    If port 5000 is already bound, use the following command to start the flask
+    app:
+
+    $ flask run -p INTEGER
+
+The app will automatically fail if there is not file containing valid JSON data
+located at ./resources/data.json. This json file should have the following data
+structure:
+
+    {
+        "stream_url":"https://yourstream.url",
+        "user_name":"admin",
+        "stream_key":"your_stream_key"
+    }
+"""
 
 import chevron
 import requests