`DefaultParameters` looks bug-prone.

[seiyab]

I think DefaultParameters tend to be unintentionally mutated. Because DefaultParameters is a pointer, following code will pollute it.

params := winrm.DefaultParameters
params.Timeout = timeout // ⚠️ Ouch! winrm.DefaultParameters is also changed!

You can see such codes even in README.md.

winrm/README.md

Lines 139 to 140 in e811dad

	params := DefaultParameters
	params.TransportDecorator = func() Transporter { return &ClientNTLM{} }

I also put a real-world example here.
https://github.com/hashicorp/terraform/blob/8f7744da0959334f461c18ccf15f8b19d8c09fe6/internal/communicator/winrm/communicator.go#L63-L64

[seiyab]

I suggest to add something like NewDefaultParameters() and add // Deprecated into DefaultParameters.