Update instructions

Assuming your checked out version of musicbrainz-docker is v-2023-05-16-mbdb28 or later, then just run:

git fetch --tags origin && \
git checkout v-2023-10-02 && \
sudo docker-compose up --build -d

Changes

• Fix slow startup of the service mq (#257)
• Upgrade MusicBrainz Server to v-2023-10-02