Enforce usage as per Use string

[ammario]

E.g., in coder/coder we have code like:

	cmd := &serpent.Cmd{
		Use:   "create [name]",
		Short: "DEPRECATED: Create a template from the current directory or as specified by flag",
		Middleware: serpent.Chain(
			serpent.RequireRangeArgs(0, 1),
			r.InitClient(client),
		),

where the serpent.RequireRangeArgs(0, 1) is arguably redundant with the Use. Also, we could provide an error message by just parsing Use.