Add community browser extension Plausible Shield that shields traffic

[xuhdev]

Plausible Shield allows a user to save a list of URL prefixes in browser and sync them via browser syncs. This can be helpful for those who owns multiple devices.

The underlying mechanics is to set the localStorage flag before the browser visiting a page under that URL.

Note that people can't specify a wild card * and abuse this browser extension to block all Plausible tracking site: The browser extension specifically requires the user to specify the portion of URL such that the full host name is known.