added multistep to docs (#1880)

Author: abidlabs

demo/blocks_speech_text_length/requirements.txt renamed to demo/blocks_speech_text_sentiment/requirements.txt

@@ -262,7 +262,7 @@ def update(name):
             btn.click(fn=update, inputs=inp, outputs=out)
 
         demo.launch()
-    Demos: blocks_hello, blocks_flipper, blocks_speech_text_length, generate_english_german
+    Demos: blocks_hello, blocks_flipper, blocks_speech_text_sentiment, generate_english_german
     """
 
     def __init__(

demo/blocks_speech_text_length/run.py renamed to demo/blocks_speech_text_sentiment/run.py

@@ -39,6 +39,11 @@ $demo_reversible_flow
 
 Note that `num1` can act as input to `num2`, and also vice-versa! As your apps get more complex, you will have many data flows connecting various Components. 
 
+Here's an example of a "multi-step" demo, where the output of one model (a speech-to-text model) gets fed into the next model (a sentiment classifier).
+
+$code_blocks_speech_text_sentiment
+$demo_blocks_speech_text_sentiment
+
 ## Function Return List vs Dict
 
 So far, you have seen event listener functions with multiple outputs return a single value for each output component, in the order listed by the event listener. For example: