Suggest cargo insta test when running cargo test

[max-sixty]

We're using insta a lot in PRQL.

A core dev wanted to split up the tests, because they were finding only the first test was replaced https://github.com/max-sixty/prql/pull/261. They had been running cargo test rather than cargo insta test.

Would it be helpful to add a comment to the "To update snapshots run cargo insta review" message that's printed to also say something like "Stopped on the first failure in {func}. Run cargo insta test to run all snapshots."

I can also write a "Contributing" guide which includes this for PRQL, but even better if it's upstreamed.

I'm happy to do a PR.

[mitsuhiko]

Fixed in d80987d. Good idea thanks!

[max-sixty]

Thanks a lot @mitsuhiko !