added description

phasehunter/app.py

@@ -116,6 +116,11 @@ model.eval()
 
 with gr.Blocks() as demo:
     gr.Markdown("# PhaseHunter")
+    gr.Markdown("""This app allows one to detect P and S seismic phases along with uncertainty of the detection. 
+                The app can be used in three ways: either by selecting one of the sample waveforms;
+                                                   or by selecting an earthquake from the global earthquake catalogue;
+                                                   or by uploading a waveform of interest.
+                """)
     with gr.Tab("Default example"):
         # Define the input and output types for Gradio
         inputs = gr.Dropdown(