Update Bastion with no public IP Linux and Windows VMs

[vanzod]

Updates the Bastion deployment example.

• The older config.json has been replaced by a revised version of the more recent config_no_pub_ip.json template. Full deployment without direct SSH access through public IP.
• The bastion_ssh_jumpbox.sh script does not need manual editing. All necessary parameters are now collected from config.json and AzCLI calls.
• Added Key Vault to store Windows VM password
• Updated README file to include latest changes.