All the instructions you need are on
the GitHub repo.
If you need any help getting setup, just respond to this thread, I'm happy to assist. If you have any feedback, raise an issue on GitHub.
I hope this is of some use to other people who use both Pinboard and TiddlyWiki. If you do not have a Pinboard account, perhaps this is a good time to give it a go? It's a simple, no-nonsense service that stores bookmarks and provides an API.
Bookmarks from your Pinboard account...
...are included in tiddlers that share the same tags.