I've been working with the folks over at the cdnjs project to get the PnP JS Core listed and am happy to announce the library is now available! This should make it easier for folks to include the library in their projects, as well as reference it in SharePoint Framework projects as an external resource.
If you aren't familiar with cdnjs they manage a github repo where you can submit libraries (yours or others) for listing. They do have some listing criteria based around popularity so keep that in mind when you submit. See how to add your library and the process is quite easy - simply fork the repo, add your library, and submit a pull request for review. One hint I have is to check out this article on sparse checkout as the repo is huge so it will save you some time. The really nice thing is that once you get things setup they have an auto update option which will automatically load the latest version of your library as it is updated (based on npm).
You can see all the links listed by version on the project landing page in the cdnjs network:
There you can select the version you want and copy the links you need. Note we have also added the map files to help you easily debug your projects while working from the CDN.