update app file

app.py

@@ -26,7 +26,16 @@ def process_paragraph(paragraph):
 
     return subheading_final
 
+
 def main():
+    css = """
+    <style>
+    textarea {
+        height: 300px;
+    }
+    </style>
+    """
+    st.markdown(css, unsafe_allow_html=True)
     st.title("Subheading Generator")
     user_input = st.text_area("Enter a paragraph: ")