adding .pre-commit-config.yaml to opm-grid

[GitPaean]

and updating the repo accoridingly.

To me, it is handy to be able to hook the pre-commit when commit, while not sure how it works for others.

Creating the PR for potential discussion and/or getting it in.

[GitPaean]

jenkins build this please

[GitPaean]

abusing this PR to generate update for https://github.com/OPM/opm-tests/pull/1344 .

[GitPaean]

jenkins build this opm-tests=1344 update_data please