Include documentation URLs for built-in rulesets

[dillan]

User story.
As a Spectral user, I can click on a documentation URL, so that I can get more context for why a rule has failed, so that I may address the issue more quickly.

Is your feature request related to a problem?
While the concise message helps me quickly understand what the issue is for a lint result, providing more context or proposed solutions can help users address the issue more quickly, accurately, and completely.

The ruleset docs like the one linked below provide a wealth of info, including both good and bad examples. This context can save Spectral uses a lot of time and frustration if they have quick access to this information. https://docs.stoplight.io/docs/spectral/4dec24461f3af-open-api-rules#oas3-server-variables

Describe the solution you'd like
For each Spectral lint result, include the documentationURL for all built-in rulesets. Especially for machine-readable output formats like JSON. Ideally, each lint result would also identify the ruleset that the failing rule came from.

Additional context
Relates to: #2443