Error on creating service principal name with docs as listed

[iennae]

Update documentation https://github.com/cloud-actions/golang-actions-functions/tree/master/azure to be clear that the RESOURCE_GROUP needs to change as the service principal is being called the same as the resource group (not the problem) but you can't have multiple service principals with the same name.

[iennae]

Also make sure to add to the DEPLOY-LINUX.sh so that it reflects the new service principal if it's changed.