docs: fix the 'list all items in a drive' sample (#1070)

docs/drives_samples.md

@@ -39,17 +39,29 @@ async def get_drive():
 asyncio.run(get_drive())
 ```
 
-## 3. LIST ALL THE ITEMS IN A DRIVE (GET /drives/{id}/items)
+## 3. LIST ALL THE ITEMS IN A DRIVE, RECURSIVELY (GET /drives/{id}/items/root/delta)
+
+`GET /drives/{id}/items` is not an enumerable collection in Microsoft Graph — it addresses
+items by id and only answers `$filter` queries, so calling it without a filter returns
+`The 'filter' query option must be provided.` To enumerate every item in a drive, walk the
+tree from the root with `delta`, which pages through the whole drive:
 
 ```py
-async def get_drive_items():
-    items = await client.drives.by_drive_id('DRIVE_ID').items.get()
-    if items and items.value:
-        for item in items.value:
-            print(item.id, item.name, item.size, item.folder, item.file)
-asyncio.run(get_drive_items())
+async def get_all_drive_items():
+    page = await client.drives.by_drive_id('DRIVE_ID').items.by_drive_item_id('root').delta.get()
+    while page:
+        if page.value:
+            for item in page.value:
+                print(item.id, item.name, item.size, item.folder, item.file)
+        if not page.odata_next_link:
+            break
+        page = await client.drives.by_drive_id('DRIVE_ID').items.by_drive_item_id('root').delta.with_url(page.odata_next_link).get()
+asyncio.run(get_all_drive_items())
 ```
 
+To list only the top level of the drive rather than recursing, use the `root/children`
+sample below (section 6).
+
 ##  4. GET AN ITEM IN THE DRIVE (GET /drives/{id}/items/{id})
 
 ```py