Add GitHub Sponsors funding link

This changes the NPM registry URL to point to the actual NPM registry
instead of the GitHub package registry.

This should hopefully fix any possible issues where the NPM package
may be released after the documentation is deployed, which could cause
a cause miss by jsDelivr and cause the documentation to cache without
pulling in the Select2 dependency.

It hasn't happened yet, but I'm concerned it could happen and I don't
want to put in the effort to make a more sophisticated way of
handling this issue.

This is needed until cdnjs figures out their future in
cdnjs/cdnjs#13524. Until then, we will just reference their existence
and promote jsDelivr to the primary source.

Fix NPM deployment

Replace cdnjs with jsDelivr in the docs

Fix support for the Shadow DOM when calculating offsets

[Release] 4.0.12