Update README.md

[ShiJieCloud]

default log level is trace , not debug

[ShiJieCloud]

from code:

// Logger is the global logger.
var Logger = zerolog.New(os.Stderr).With().Timestamp().Logger()

func New(w io.Writer) Logger {
if w == nil {
w = ioutil.Discard
}
lw, ok := w.(LevelWriter)
if !ok {
lw = LevelWriterAdapter{w}
}
return Logger{w: lw, level: TraceLevel}
}```