Remove import_dandisets command from docs

DEVELOPMENT.md

@@ -146,40 +146,6 @@ This creates a dummy dandiset with valid metadata and a single dummy asset.
 The dandiset should be valid and publishable out of the box.
 This script is a simple way to get test data into your DB without having to use dandi-cli.
 
-### import_dandisets
-```
-python manage.py import_dandisets [API_URL] --all
-```
-
-This imports all dandisets (versions + metadata only, no assets) from the dandi-api deployment
-living at `API_URL`. For example, to import all dandisets from the production server into your
-local dev environment, run `python manage.py import_dandisets https://api.dandiarchive.org` from
-your local terminal. Note that if a dandiset with the same identifier as the one being imported
-already exists, that dandiset will not be imported.
-
-```
-python manage.py import_dandisets [API_URL] --all --replace
-```
-
-Same as the previous example, except if a dandiset with the same identifier as the one being imported
-already exists, the existing dandiset will be replaced with the one being imported.
-
-```
-python manage.py import_dandisets [API_URL] --all --offset 100000
-```
-
-This imports all dandisets (versions + metadata only, no assets) from the dandi-api deployment
-living at `API_URL` and offsets their identifiers by 100000. This is helpful if you want to import
-a dandiset that has the same identifier as one already in your database.
-
-```
-python manage.py import_dandisets [API_URL] --identifier 000005
-```
-
-This imports dandiset 000005 from `API_URL` into your local dev environment. Note that if there is already
-a dandiset with an identifier of 000005, nothing will happen. Use the --replace flag to have the script
-overwrite it instead if desired.
-
 ## Abbreviations
 
 - DLP: Dataset Landing Page (e.g. https://dandiarchive.org/dandiset/000027)