Update 15_2_Wasserstein_Distance.ipynb

Scaling of the distance matrix was not mentioned in the book.

Notebooks/Chap15/15_2_Wasserstein_Distance.ipynb

@@ -86,6 +86,8 @@
       "cell_type": "code",
       "source": [
         "# TODO Define the distance matrix from figure 15.8d\n",
+        "# Each element (i, j) in the distance matrix represents the absolute difference between positions i and j,\n",
+        "# scaled by the maximum possible distance to ensure the values lie within [0, 1].\n",
         "# Replace this line\n",
         "dist_mat = np.zeros((10,10))\n",
         "\n",