updated run.py to start flask server and added a default route for webpage

run.py

@@ -1,3 +1,17 @@
 from flask import Flask
 
+# Create Flask instance
 app = Flask("__name__")
+
+
+# Default app route
+@app.route("/")
+def index():
+    # Return HTML content
+    return "<h1>This is the default page</h1>"
+
+
+# Prevent execution when imported by other script
+if __name__ == "__main__":
+    # Start the flask server in debug mode for development purposes
+    app.run(port=80, debug=True)