1303.feature: add yamlfmt in pre-commit

[even-even]

Hello.

In this PR:

1. add https://github.com/google/yamlfmt for formatting .yaml files
2. formatting .yaml files after run pre-commit

[webknjaz]

Can it be configured to retain current format? Overly indented stuff takes up too much space. I've found that only yamllint is capable of enforcing good style.

[RonnyPfannschmidt]

closing due to lack of feedback and drift, happy to review something that better manages indentation