Update Grouping.ipynb

Minor typo fix

Author: WillieMaddox

Part 2/Section 08 - Iteration Tools/08 - Grouping/Grouping.ipynb

@@ -757,7 +757,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The key thing here is that the elements yielded from the different groups are using the **same** undelying iterable over all the elements. As the documentation states, when we advance to the next group, the previous one's iterator is automatically exhausted - it basically iterates over all the elements until it hits the next group key.\n",
+    "The key thing here is that the elements yielded from the different groups are using the **same** underlying iterable over all the elements. As the documentation states, when we advance to the next group, the previous one's iterator is automatically exhausted - it basically iterates over all the elements until it hits the next group key.\n",
     "\n",
     "Let's see this by stepping through the iteration manually:"
    ]