fix: make yaml output pass ansible-lint

[gardar]

• Adds yaml boundary marker --- to the header of the file.
• Increases indentation level on list items.

fixes: #91
fixes: #152

[gardar]

Not sure if what the nox linter is complaining about is related to my changes.

src/antsibull_changelog/changes.py:702: error: Call to abstract method "sort" of "ChangesBase" with trivial body via super() is unsafe  [safe-super]

[felixfontein]

Thanks for your contribution! Please make this behavior configurable. It should not be the default IMO.

(#161 fixes the mypy linting error; it is due to a newer version of mypy.)

[gardar]

Ok sure, although I don't see what harm it could do to have it as the default format.
How do you propose I make it configurable? Do you want a new parameter?

[felixfontein]

Ok sure, although I don't see what harm it could do to have it as the default format.

This causes huge changes in changelogs/changelog.yaml in many collections.

How do you propose I make it configurable? Do you want a new parameter?

I would add a setting to changelogs/config.yaml.

[gardar]

I would add a setting to changelogs/config.yaml.

@felixfontein this should be all ready now.

[felixfontein]

Looks good to me!

[felixfontein]

@gardar thanks for your contribution!
@gotmax23 thanks for reviewing!