Sql 2016 alwayson changes

[dbrennand]

👋 Hello,

I have made a few changes to the sql-2016-alwayson Readme.md and azuredeploy.parameters.json.

Changes

• Changed "Two for each SQL VM" to "One ..." as only one for each is deployed. Adding up to four total.
• Changed "One availability set" to "Two". Two are deployed in the ARM template.
• Removed clustered as an option. The allowed values for the parameter sqlServerSku in azuredeploy.json only allow Enterprise, Standard and SQLDEV.
• Fixed a typo for the adminUsername parameter in azuredeploy.parameters.json.
• Changed the value for the parameter domainName in azuredeploy.parameters.json to be in line with the default value in azuredeploy.json

[msftclas]

All CLA requirements met.