Update QRC Demo MNIST.ipynb

QRC Demo MNIST.ipynb

@@ -1943,7 +1943,7 @@
    "source": [
     "1. How does the QRC perform if we only collect $\\langle Z_i\\rangle $ expectation values and drop $\\langle Z_i Z_j\\rangle $ correlations? Why do you think this happens? How about adding connected $\\langle Z_i Z_j Z_k\\rangle$, where $\\{i, j, k\\}$ are a cluster of sites connected by the nearest neighbor bonds?\n",
     "\n",
-    "Hint: Try to modify the readouts vector to modify correlations calculated."
+    "Hint: Try to modify the readouts vector to exclude/include the correlations that are calculated."
    ]
   },
   {