Return errors instead of logging/go modules/comments

[KatamariJr]

• Added go.mod file to support modules.
• It is more useful to return the errors rather than logging them, whatever code calls this library would be the one that should actually handle logging, and it makes more sense to wrap that error that gets returned instead.
• Cleaned up the comments, as they seemed to be outdated/not written as well as they could be.

Also, if you merge this, you should tag it as v1.0.0