reference docs are incorrectly linked

[binyamin]

There are links to https://maronato.github.io/plausible-tracker/. It should be https://plausible.github.io/plausible-tracker/. This is present in the repository metadata, as well as the bottom of the readme.

While we're at it, the readme and metadata say that it's unofficial. That should probably be changed, since this repo is under the plausible org.