fix typos and add explanation

app.py

@@ -20,8 +20,8 @@ def _classifier(inp):
 
 iface = gr.Interface(fn=_classifier, 
                       title="Disaster damage assessment from social media image",
-                      description="This simple app allow users to load an image and assess the extent of damage cause by an earthquake",
-                      article="The severity of damage in an image is the extent of physical destruction shown in it. For this experiment we only consider three level of damages :severe damage,mild damage and no damage (none)",
+                      description="This simple app allow users to load an image and assess the extent of damage caused by an earthquake",
+                      article="The severity of damage in an image is the extent of physical destruction shown in it. For this experiment we only consider three level of damages: severe damage,mild damage and no damage (none). The model was trained using data from Haiti,Ecuador,Nepal earthquakes and google images.",
                       examples=['Haiti-Gingerbread-2.jpg','building_damage_100.jpg','building_damage_424.jpg'],
                      inputs=gr.inputs.Image(shape=(IMG_SIZE, IMG_SIZE)),
                      outputs=gr.outputs.Label()