Fix mistakes in register example (#681)

* Fix mistakes in register examples

* Fix indentation and use enum.

Co-authored-by: Padraic Shafer <[email protected]>

* Import enum

Co-authored-by: Padraic Shafer <[email protected]>

* Add structure

---------

Co-authored-by: Padraic Shafer <[email protected]>

docs/source/how-to/register.md

@@ -76,22 +76,37 @@ Use the Python client, as in this example.
 
 ```py
 from tiled.client import from_uri
-from tiled.client.data_source import Asset, DataSource
 from tiled.structures.core import StructureFamily
+from tiled.structures.data_source import Asset, DataSource, Management
+from tiled.structures.array import ArrayStructure, BuiltinDtype
 
 # You can pass the api_key in explicitly as shown here, but for security, it
 # is best to set the API key in the environment variable TILED_API_KEY, which
 # from_uri(...) will automatically detect and use.
 client = from_uri("http://localhost:8000", api_key="...")
 
+structure = ArrayStructure(
+    dtype=BuiltinDtype.from_numpy_dtype(numpy.int32),
+    shape=(2, 512, 512),
+    chunks=((1, 1), (512,), (512,)),
+    dims=("time", "x", "y"),  # optional
+)
+
 # POST /api/v1/register/{path}
 client.new(
     structure_family=StructureFamily.array,
-    data_sources=DataSource(
-    	assets=[Asset(data_uri="file:///...", num=1), Asset(data_uri="file:///...", num=2)],
-	mimetype="multipart/related;type=image/tiff",
-	structure_family=StructureFamily.array,
-    ),
+    data_sources=[
+        DataSource(
+            management=Management.external,
+            mimetype="multipart/related;type=image/tiff",
+            structure_family=StructureFamily.array,
+	    structure=structure,
+            assets=[
+                Asset(data_uri="file:///...", num=1),
+                Asset(data_uri="file:///...", num=2),
+            ],
+        ),
+    ],
     metadata={},
     specs=[],
 )