Disruption doc: determine how to generate and update query_results.json

pkg/synthetictests/allowedbackenddisruption/query_results.json is used to determine if a disruption test passes or fails. It is data that is obtained by the data collected from BigQuery.

We need to determine how it's generated it and document the procedure in ci-docs repo.

Also, add some info on how the fuzzy matching works for jobs that are not represented in the data; see some code