Add Zally linter

[pmcelhaney]

I just discovered this tool. Surprised it's not listed here already.

[philsturgeon]

@pmcelhaney have you found this tool to be useful? I have been aware of it for years but it's never seemed particulary handy as its mostly telling you how to build APIs like Zalanda want, which Spectral/Vacuum can do using this ruleset: https://github.com/baloise-incubator/spectral-ruleset/blob/main/zalando.yml

Otherwise it's asking for people to write Kotlin which... is that something people want to do just to check an API is compliant? The other linters use simple DSLs or even human sentences. https://www.useoptic.com/lintgpt

[pmcelhaney]

Thanks. I haven't used it personally. I saw someone else using it. Up to that point I wasn't even aware that OpenAPI linters were a thing.

If there are better alternatives, and this isn't intended to be a comprehensive catalog of everything out there, feel free to close this PR. :)

[philsturgeon]

Cool, thank you. I'd point to Spectral, Redocly CLI (review), or LintGPT (review coming soon).