add docs for with_config

Author: d-v-b

docs/user-guide/arrays.md

@@ -154,6 +154,32 @@ z.append(np.vstack([a, a]), axis=1)
 print(f"Shape after second append: {z.shape}")
 ```
 
+## Runtime configuration
+
+Zarr arrays are parametrized with a configuration that determines certain aspects of array behavior.
+
+We currently support two configuration options for arrays: `write_empty_chunks` and `order`.
+
+| field | type | default | description |
+| - |     - | - | - |
+| `write_empty_chunks` | `bool` | `False` | Controls whether empty chunks are written to storage. See [Empty chunks](performance.md#empty-chunks).
+| `order` | `Literal["C", "F"]` | `"C"` | The memory layout of arrays returned when reading data from the store.
+
+You can specify the configuration when you create an array with the `config` keyword argument.
+`config` can be passed as either a `dict` or an `ArrayConfig` object.
+
+```python exec="true" session="arrays" source="above" result="ansi"
+arr = zarr.create_array({}, shape=(10,), dtype='int8', config={"write_empty_chunks": True})
+print(arr.config)
+```
+
+To get an array view with a different config, use the `with_config` method.
+
+```python exec="true" session="arrays" source="above" result="ansi"
+arr_f = arr.with_config({"order": "F"})
+print(arr_f.config)
+```
+
 ## Compressors
 
 A number of different compressors can be used with Zarr. Zarr includes Blosc,