Update documentation

Author: AllenDowney

_sources/chap10.ipynb

@@ -1631,7 +1631,7 @@
     "\n",
     "As you work with bigger datasets it can become unwieldy to debug by printing and checking the output by hand. Here are some suggestions for debugging large datasets:\n",
     "\n",
-    "1) Scale down the input: If possible, reduce the size of the dataset. For example if the\n",
+    "1.  Scale down the input: If possible, reduce the size of the dataset. For example if the\n",
     "    program reads a text file, start with just the first 10 lines, or\n",
     "    with the smallest example you can find. You can either edit the\n",
     "    files themselves, or (better) modify the program so it reads only\n",