Fix formatting

The recall formula wasn't rendering properly.

notebooks/metrics_classification.ipynb

@@ -311,12 +311,12 @@
     "blood when the classifier predicted so or the fraction of people predicted to\n",
     "have given blood out of the total population that actually did so.\n",
     "\n",
-    "The former metric, known as the precision, is defined as TP / (TP + FP) and\n",
+    "The former metric, known as the precision, is defined as `TP / (TP + FP)` and\n",
     "represents how likely the person actually gave blood when the classifier\n",
-    "predicted that they did. The latter, known as the recall, defined as TP / (TP\n",
-    "+ FN) and assesses how well the classifier is able to correctly identify\n",
-    "people who did give blood. We could, similarly to accuracy, manually compute\n",
-    "these values, however scikit-learn provides functions to compute these\n",
+    "predicted that they did. The latter, known as the recall, defined as \n",
+    "`TP / (TP + FN)` and assesses how well the classifier is able to correctly \n",
+    "identify people who did give blood. We could, similarly to accuracy, manually\n",
+    "compute these values, however scikit-learn provides functions to compute these\n",
     "statistics."
    ]
   },