docs/admin: update music importing documentation

It still referenced pre-1.0 functionality
8 jobs for installation-update in 11 minutes and 59 seconds (queued for 7 seconds)
Status Name Job ID Coverage
  Review
manual review_docs #76289
docker allowed to fail manual
manual review_front #76288
docker allowed to fail manual
 
  Lint
passed black #76290

00:00:37

passed eslint #76292

00:01:49

passed flake8 #76291

00:00:23

 
  Test
passed test_api #76293
docker

00:09:04

passed test_front #76294
docker

00:01:17

 
  Deps
failed check_api_dependencies #76295
docker allowed to fail

00:00:04

 
Name Stage Failure
failed
check_api_dependencies Deps
Running with gitlab-runner 14.1.0 (8925d9a0)
on global dind for fw uPB1dYxh
Preparing the "docker" executor
Using Docker executor with image dev.funkwhale.audio:5050/xeruf/funkwhale:installation-update ...
Authenticating with credentials from job payload (GitLab Registry)
Pulling docker image dev.funkwhale.audio:5050/xeruf/funkwhale:installation-update ...
WARNING: Failed to pull image with policy "always": Error response from daemon: manifest for dev.funkwhale.audio:5050/xeruf/funkwhale:installation-update not found: manifest unknown: manifest unknown (manager.go:205:0s)
ERROR: Job failed: failed to pull image "dev.funkwhale.audio:5050/xeruf/funkwhale:installation-update" with specified policies [always]: Error response from daemon: manifest for dev.funkwhale.audio:5050/xeruf/funkwhale:installation-update not found: manifest unknown: manifest unknown (manager.go:205:0s)