Update Twing "autoupdate" to its proper GitHub repository

[ericmorand]

As discussed there, I moved the browser-dedicated bundle of Twing to its own GitHub repository, in order to both reduce the size of twing's npm package and still benefit from the autoupdate feature of cdnjs.

Note that I'm not 100% sure what value is expected for basePath when the files are located at the root of the project. I set the value to an empty string, please let me know if this is not correct.

EDIT: Oh, I see that one of the checks actually retrieves the file. Since it is a success, it means that I did set basePath correctly.