getting rid of console.error

[kk1694]

Could we get rid of the console.error statements in the code? It's very convoluted to disable this outside of the library.

(Error logs of the form Should not have tags except <li> inside ul.... This does not raise an exception, but prints out errors.

I can see a few options:

• add a printLogs options that users can disable error logs with
• raise errors and let the users handle exceptions on their side (or log it however they want).

Happy to submit a PR with either of these options, or whatever you deem best.