fsnotify doesn't work with Windows, polling does

The simple example in the README doesn't work with Windows 10 Pro x64 (Version 10.0.19042 Build 19042).
Adding `Poll: true`, insted, works:

```go
t, err := tail.TailFile(fpath, tail.Config{Follow: true, Poll: true})
for line := range t.Lines {
	fmt.Println(line.Text)
}
```

I think you could mention it in the README