Update Validator Upgrade Instructions with New Example PR

jobs/gtfs-schedule-validator/README.md

@@ -10,13 +10,12 @@ of the underlying data. The RT code was written prior to substantial changes to
 `calitp-py` and therefore bundles together shared functionality that will eventually
 live in `calitp-py`.
 
-See [this PR](https://github.com/cal-itp/data-infra/pull/2893) for an example of how
-to integrate new versions of the underlying MD-stewarded validator into our validation
-process - specifically, changes to [`gtfs_schedule_validator_hourly.py`](https://github.com/cal-itp/data-infra/pull/2893/files#diff-f970d61c9ce49b3899e7b309610f43fca51d29eaae4d5db192208540bc4da702) and
-[the `Dockerfile`](https://github.com/cal-itp/data-infra/pull/2893/files#diff-de54f054016ca4e44544d4081d2798a21aa43790c3faea3967f6f5b255529f1a), and the
-addition of [a new JAR file](https://github.com/cal-itp/data-infra/pull/2893/files#diff-628dcc44a01286366e42ab8fd440d213d764d8a76f41f268e378a14628e8447c)
-corresponding to the new validator version being referenced (taken from the Assets
-section at the bottom of [the new validator version's release page](https://github.com/MobilityData/gtfs-validator/releases/tag/v4.1.0)).
+See [this PR](https://github.com/cal-itp/data-infra/pull/3238) for an example of how to
+integrate new versions of the underlying MD-stewarded validator into our validation
+process - note the addition of a new JAR file corresponding to the new validator version
+being referenced (taken from the Assets section at the bottom of [the new validator version's release page](https://github.com/MobilityData/gtfs-validator/releases/tag/v4.2.0)),
+and a corresponding list of rules and their short descriptions adopted from the canonical
+validator [rules list](https://gtfs-validator.mobilitydata.org/rules.html).
 
 In order to respect past validation outcomes, we don't re-validate old data using the latest
 available version of the validator. Instead, we use extract dates to determine which