Add more examples to the phi readme. (#956)

candle-examples/examples/phi/README.md

@@ -1,6 +1,11 @@
 # candle-phi: 1.3b LLM with state of the art performance for <10b models.
 
-[phi-1.5](https://huggingface.co/microsoft/phi-1_5).
+[Phi-1.5](https://huggingface.co/microsoft/phi-1_5) is a language model using
+only 1.3 billion parameters but with state of the art performance compared to
+models with up to 10 billion parameters.
+
+The candle implementation provides both the standard version as well as a
+quantized variant.
 
 ## Running some example
 
@@ -20,4 +25,19 @@ def is_prime(n):
         if n % i == 0:
             return False
     return True
+
+$ cargo run --example phi --release -- \
+  --prompt "Explain how to find the median of an array and write the corresponding python function.\nAnswer:" \
+  --quantized --sample-len 200
+
+Explain how to find the median of an array and write the corresponding python function.
+Answer: The median is the middle value in an array. If the array has an even number of elements, the median is the average of the two middle values.
+
+def median(arr):
+    arr.sort()
+    n = len(arr)
+    if n % 2 == 0:
+        return (arr[n//2 - 1] + arr[n//2]) / 2
+    else:
+        return arr[n//2]
 ```