feat: Add option to generate markdownDescription

[Jason3S]

fixes #1544

I have been running into a lot of trouble generating schemas that can be use by VS Code to display readable descriptions if they contain markdown.

I saw #1544 and took the approach of adding a new option: --markdown-description. This option will will cause markdownDescription to be generated as well a description.

Note: this option will only populate markdownDescription is will not parse it or attempt to validate that the markdown is valid. I think that is beyond the scope of this PR.

Markdown validation could be done at a later date.

[Jason3S]

Thoughts

Implicit keyword markdownDescription

In this PR, the markdownDescription key word must be explicitly added as an option. This might lead to some unexpected behavior for some users that might also use @markdownDescription tags. A solution is to add markdownDescription as a keyword if option --markdownDescription is used.

Option --validation-keywords=markdownDescription

If a user explicitly adds keyword markdownDescription, it implies option --markdownDescription.

[Jason3S]

@domoritz,

Gentle nudge.

[domoritz]

Thank you. Looks good and I'll merge.

I'll consider this option beta for now until @remcohaszing and @GeekyEggo had a chance to review the behavior or enough time passes. So changes are possible without a major version bump.

[github-actions]

🚀 PR was released in v1.4.0 🚀

[remcohaszing]

Thanks! I think it looks great. markdownDescription isn’t processed, which is good.

I still think the processing of description without context is dangerous, because nothing in plain text has a semantic meaning. But that’s left untouched by this PR.

[GeekyEggo]

Thank you for this addition; I’ve ran some local tests and everything looks good! 🙌