Custom log level names with color

[nasdf]

It'd be great to be able to customize the log level names and keep the colors.

I think simple package level variables would work for most use cases.

var (
  InfoLevelName  = "INF"
  ErrorLevelName = "ERR"
)

Happy to submit a PR if you agree with the feature.

[lmittmann]

This is a popular request. You can currently customize levels via the ReplaceAttr option. But I agree that it is not very handy, since you need to manage colors on your own. I am not sure how the API could look like yet, but modifying global variables is not the way.

[iamsumit]

Raised a PR to provide this feature.