Update entity-framework/core/cli/dotnet.md

Author: Rick-Anderson

entity-framework/core/cli/dotnet.md

@@ -263,6 +263,8 @@ The following example skips scaffolding an `OnConfiguring` method. This can be u
 
 ```dotnetcli
 dotnet ef dbcontext scaffold "Server=(localdb)\mssqllocaldb;Database=Blogging;User Id=myUsername;Password=\0;" Microsoft.EntityFrameworkCore.SqlServer --no-onconfiguring
+
+In the preceding code, replace `\0` with a valid strong password.
 ```
 
 ## `dotnet ef dbcontext script`