Added documentation for Location swap migration (#2440)

Author: mnocon

code_samples/data_migration/examples/swap_location.yaml

@@ -0,0 +1,9 @@
+-
+    type: location
+    mode: swap
+    match1:
+        field: location_remote_id
+        value: f3e90596361e31d496d4026eb624c983
+    match2:
+        field: location_id
+        value: 5

docs/content_management/data_migration/importing_data.md

@@ -49,31 +49,31 @@ Then, the step is described by additional properties depending on its type and m
 
 The following data migration step modes are available:
 
-| `type`                 | `create` | `update` | `delete` |
-|------------------------|:--------:|:--------:|:--------:|
-| `attribute`            | ✔ | ✔ | ✔ |
-| `attribute_group`      | ✔ | ✔ | ✔ |
-| `content_type`         | ✔ | ✔ | ✔ |
-| `content_type_group`   | ✔ | ✔ | ✔ |
-| `content`              | ✔ | ✔ | ✔ |
-| `currency`             | ✔ | ✔ | ✔ |
-| `customer_group`       | ✔ | ✔ | ✔ |
-| `language`             | ✔ |          |          |
-| `location`             |          | ✔ |          |
-| `object_state`         | ✔ |          |          |
-| `object_state_group`   | ✔ |          |          |
-| `payment_method`       | ✔ |          |          |
-| `product_asset`        | ✔ |          |          |
-| `product_availability` | ✔ |          |          |
-| `product_price`        | ✔ |          |          |
-| `product_variant`      | ✔ |          |          |
-| `role`                 | ✔ | ✔ | ✔ |
-| `section`              | ✔ | ✔ |          |
-| `segment`              | ✔ | ✔ | ✔ |
-| `segment_group`        | ✔ | ✔ | ✔ |
-| `setting`              | ✔ | ✔ | ✔ |
-| `user`                 | ✔ | ✔ |          |
-| `user_group`           | ✔ | ✔ | ✔ |
+| `type`                 | `create` | `update` | `delete` | `swap`   |
+|------------------------|:--------:|:--------:|:--------:|:--------:|
+| `attribute`            | ✔ | ✔ | ✔ |          |
+| `attribute_group`      | ✔ | ✔ | ✔ |          |
+| `content_type`         | ✔ | ✔ | ✔ |          |
+| `content_type_group`   | ✔ | ✔ | ✔ |          |
+| `content`              | ✔ | ✔ | ✔ |          |
+| `currency`             | ✔ | ✔ | ✔ |          |
+| `customer_group`       | ✔ | ✔ | ✔ |          |
+| `language`             | ✔ |          |          |          |
+| `location`             |          | ✔ |          | ✔ |
+| `object_state`         | ✔ |          |          |          |
+| `object_state_group`   | ✔ |          |          |          |
+| `payment_method`       | ✔ |          |          |          |
+| `product_asset`        | ✔ |          |          |          |
+| `product_availability` | ✔ |          |          |          |
+| `product_price`        | ✔ |          |          |          |
+| `product_variant`      | ✔ |          |          |          |
+| `role`                 | ✔ | ✔ | ✔ |          |
+| `section`              | ✔ | ✔ |          |          |
+| `segment`              | ✔ | ✔ | ✔ |          |
+| `segment_group`        | ✔ | ✔ | ✔ |          |
+| `setting`              | ✔ | ✔ | ✔ |          |
+| `user`                 | ✔ | ✔ |          |          |
+| `user_group`           | ✔ | ✔ | ✔ |          |
 
 ### Repeatable steps
 
@@ -308,6 +308,15 @@ The following example shows how to delete the `Contributor` Role:
 [[= include_file('code_samples/data_migration/examples/delete_role.yaml') =]]
 ```
 
+### Locations
+
+The following example shows how to swap content items assigned to given locations.
+
+``` yaml
+[[= include_file('code_samples/data_migration/examples/swap_location.yaml') =]]
+```
+
+
 ### Users
 
 The following example shows how to create a user.