docs: updating the creating-a-custom-materialization-engine.md docs to work with the latest import paths (feast-dev#5315)

Signed-off-by: Dan Baron <[email protected]>

Author: danbaron63

README.md

@@ -207,6 +207,7 @@ The list below contains the functionality that contributors are planning to deve
 * **Feature Serving**
   * [x] Python Client
   * [x] [Python feature server](https://docs.feast.dev/reference/feature-servers/python-feature-server)
+  * [x] [Feast Operator (alpha)](https://github.com/feast-dev/feast/blob/master/infra/feast-operator/README.md)
   * [x] [Java feature server (alpha)](https://github.com/feast-dev/feast/blob/master/infra/charts/feast/README.md)
   * [x] [Go feature server (alpha)](https://docs.feast.dev/reference/feature-servers/go-feature-server)
   * [x] [Offline Feature Server (alpha)](https://docs.feast.dev/reference/feature-servers/offline-feature-server)

docs/how-to-guides/customizing-feast/creating-a-custom-materialization-engine.md

@@ -18,16 +18,17 @@ The fastest way to add custom logic to Feast is to extend an existing materializ
 
 #### Step 1: Define an Engine class
 
-The first step is to define a custom materialization engine class. We've created the `MyCustomEngine` below.
+The first step is to define a custom materialization engine class. We've created the `MyCustomEngine` below. This python file can be placed in your `feature_repo` directory if you're following the Quickstart guide.
 
 ```python
-from typing import Any, Callable, Dict, List, Optional, Sequence, Tuple, Union
+from typing import List, Sequence, Union
 
 from feast.entity import Entity
 from feast.feature_view import FeatureView
 from feast.batch_feature_view import BatchFeatureView
 from feast.stream_feature_view import StreamFeatureView
-from feast.infra.materialization import LocalMaterializationEngine, LocalMaterializationJob, MaterializationTask
+from feast.infra.materialization.local_engine import LocalMaterializationJob, LocalMaterializationEngine
+from feast.infra.common.materialization_job import MaterializationTask
 from feast.infra.offline_stores.offline_store import OfflineStore
 from feast.infra.online_stores.online_store import OnlineStore
 from feast.repo_config import RepoConfig