NewCommand creates a new Cobra command and a Runner to handle the command's logic, and adds flags to the command for workspace, resource group, environment name, force and context.

NewRunner creates a new instance of the `rad workspace create` runner.

ValidateArgs checks if the number of arguments passed to the command is between 1 and 2, and if the first argument is "kubernetes", and returns an error if either of these conditions are not met.

Runner is the runner implementation for the `rad workspace create` command.