Multiple wrong commands in setup.sh

Trying to reverse engineer the script setup.sh to understand how to use this plugin, I discovered mutiple commands wrong.

* `notation key remove` should be `notation key delete`
* `notation cert remove` should be `notation cert delete`

* `notation key add --name $keyName --plugin azure-kv --id $keyID --kms` should be `notation key add --plugin azure-kv --id $keyID $keyName`

* `notation cert add --name $keyName --plugin azure-kv --id $keyID --kms` is not usable at all... The cert should be a local PEM imported.
Could eventualy be :
```
az keyvault certificate download --encoding PEM --name $keyName --vault-name $keyVaultName --file tmpcert.pem
notation cert add --store test --type signingAuthority tmpcert.pem
```