Fix docs after rebase

docs/streamingdataframe.md

@@ -17,8 +17,8 @@ app = Application(
 )
 
 # Define the input and output topics. By default, the "json" serialization will be used
-input_topic = app.topic("my_input_topic")
-output_topic = app.topic("my_output_topic")
+input_topic = app.topic("input")
+output_topic = app.topic("output")
 
 
 def add_one(data: dict):
@@ -53,8 +53,8 @@ sdf = sdf[(sdf["field_0"] > 10) & (sdf["field_2"] != "test")]
 # You may also use a custom function to filter data
 sdf = sdf.filter(lambda v: v["field_0"] > 10 and v["field_2"] != "test")
 
-# Apply custom function to transform the message
-sdf = sdf.apply(add_one)
+# Apply custom function to update values in place
+sdf = sdf.update(add_one)
 
 # Use a stateful function in persist data into the state store 
 # and update the message value
@@ -372,6 +372,8 @@ input_topic = app.topic("input", key_deserializer='str')
 # Outgoing key will be serialized as a string too
 output_topic = app.topic("my_output_topic", key_serializer='str')
 
+sdf = app.dataframe(input_topic)
+
 # Producing a new message to a topic with the same key
 sdf = sdf.to_topic(output_topic)