Fix demo pipeline 2

app.py

@@ -7,9 +7,13 @@ st.title('GPT Detection Demo')
 # Add 4 options for 4 models
 option = st.sidebar.selectbox(
     'Which pipeline do you want to use?',
-        ('sentiment-analysis'),
+    ('sentiment-analysis', 'ner', 'question-answering', 'text-generation'),
 )
 
+option2 = st.sidebar.selectbox(
+    'Which model do you want to use?',
+    ('gpt2', 'gpt2-medium', 'gpt2-large', 'gpt2-xl'),
+)
 
 pipe = pipeline(option)
 text = st.text_area('Enter text here', 'Type here')