Adding YAML formatter

[leahwicz]

resolves #137

Problem

Have a linter and formatter for GitHub workflows

Solution

This is one possible solution after looking at a few possibilities here is a summary of my findings

Linter Options

• [Top vote] check-yaml @ https://github.com/pre-commit/pre-commit-hooks - we actually are already using this so unless we are looking for more from a linter, we have this covered
• yamllint @ https://github.com/adrienverge/yamllint - this is extremely configurable which is nice but it doesn't autofix the files for you and instead you have to manually do it which is a pain

Formatter Options

• [Top vote] pretty-format-yaml @ https://github.com/macisamuele/language-formatters-pre-commit-hooks - does the job for indentation and line width if that's the prime focus. Will autofix for the developer. Actually is nice with keeping quotations persistent if we want to enable that.
• yamlfmt @ https://github.com/jumanjihouse/pre-commit-hook-yamlfmt - forces each file to start with --- which isn't really the style that we are currently abiding by unless we want to change
• yamlfmt @ https://github.com/google/yamlfmt (requires Go) - the Go setup seems overkill for nothing extra

This PR shows the top vote options enabled and their changes.

I have it only enabled for GitHub workflow files at the moment. I also had it format the .pre-commit-config.yaml file as well since it was all over the place. If we enable it for all YAML files then a bunch of the changie files will change which I'm not sure how that would impact changie at the moment.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[leahwicz]

@mikealfare I listed what I found on each of the options for linters and formatters above and why I picked these 2. I didn't see too many other options that looked any different out there. Let me know if this is what you were hoping the for linter and formatter to achieve.

I know you mentioned kebab casing, capitalization, etc. standardizing as well but none of the formatters are enforcing things like that so we would have to look at some more extensive tooling if you want that kind of standard enforced.

[mikealfare]

Do you know why this list gets indented whereas lists in other files, e.g. pre-commit-config.yaml align the bullets with the parent node?

[mikealfare]

We should either make this a long form list (like black's args) or make other lists short form. I think one of the formatters also had an option for enforcing that automatically.

[mikealfare]

@mikealfare I listed what I found on each of the options for linters and formatters above and why I picked these 2. I didn't see too many other options that looked any different out there. Let me know if this is what you were hoping the for linter and formatter to achieve.

I know you mentioned kebab casing, capitalization, etc. standardizing as well but none of the formatters are enforcing things like that so we would have to look at some more extensive tooling if you want that kind of standard enforced.

Thanks for the PR @leahwicz! I agree with your assessment above. I left two comments. Let me know your thoughts.