fix missing xmldocs for AddRow/NewRow methods
fix missing xmldocs for AddRow/NewRow methods

Overlord-Zurg/FSharp.Data.SqlClient,philipcpresley/FSharp.Data.SqlClient,vikranthc/FSharp.Data.SqlClient,philipcpresley/FSharp.Data.SqlClient,vikranthc/FSharp.Data.SqlClient,Overlord-Zurg/FSharp.Data.SqlClient