Fixing broken entity key link in quickstart

Signed-off-by: Danny Chiao <danny@tecton.ai>

examples/quickstart/quickstart.ipynb

@@ -720,7 +720,7 @@
         "### Quick note on entity keys\n",
         "Note from the above command that the online store indexes by `entity_key`. \n",
         "\n",
-        "[Entity keys](https://docs.feast.dev/concepts/data-model-and-concepts#entity-key) include a list of all entities needed (e.g. all relevant primary keys) to generate the feature vector. In this case, this is a serialized version of the `driver_id`. We use this later to fetch all features for a given driver at inference time."
+        "[Entity keys](https://docs.feast.dev/getting-started/concepts/entity#entity-key) include a list of all entities needed (e.g. all relevant primary keys) to generate the feature vector. In this case, this is a serialized version of the `driver_id`. We use this later to fetch all features for a given driver at inference time."
       ]
     },
     {