Consider having an optional list of examples websites

[philipp-classen]

Looking at patterns alone is often difficult without having real-world examples.

When adding new entries, we typically have an example; but eventually that knowledge gets lost. Sometimes, WhoTracks.me can produce examples (by searching), but only if the pattern is being used on a website with enough traffic.

We could start including one or two examples in the pattern file as an optional list. As an alternative, we could start using the notes section in the beginning.