This allows tokenfilters to be applied selectively, depending on the status of the current token in the tokenstream. The filter takes a scripted predicate, and only applies its subfilter when the predicate returns true.
This commit adds two pieces. The first is a small set of documentation providing
instructions on how to get setup to run context examples. This will require a download
similar to how Kibana works for some of the examples. The second is an ingest processor
example using the downloaded data. More examples will follow as ideally one per PR.
This also adds a set of tests to individually test each script as a unit test.