Ushuaianet tutorial: missing steps

[denver-s]

1. It would be much easier if everything about shadownet was renamed ushuaianet for consistency.
2. Specify that the tutorial is made for Ubuntu (./scripts/install_octez_ubuntu.sh)
3. Is Octez v25-rc1 needed? Probably yes.
4. It is not clear how to to fix this (DAL fee view material):

./scripts/shadownet_operator_preflight.sh /etc/tzel/shadownet.env
ok: octez-node -> /usr/bin/octez-node
ok: octez-client -> /usr/bin/octez-client
ok: octez-dal-node -> /usr/bin/octez-dal-node
ok: octez-smart-rollup-node -> /usr/bin/octez-smart-rollup-node
ok: tzel-operator -> /usr/local/bin/tzel-operator
ok: rollup config admin build env -> /usr/local/etc/tzel/rollup-config-admin-build.env
ok: operator bearer token -> /etc/tzel/operator-bearer-token
missing operator DAL fee view material: /etc/tzel/operator-dal-fee.view.json