Qualify rule names to simplify extending the ruleset

[DawMatt]

Currently this ruleset uses simple rule names like "content-type". If you want to extend this ruleset, simple, unqualified names like this increase the chances of name clashes when combining them with other rulesets.

The OWASP ruleset ( https://github.com/stoplightio/spectral-owasp-ruleset/blob/main/src/ruleset.ts ) uses a URN style naming scheme that makes name clashes extremely unlikely. Changing the rule names of the JSON:API spectral ruleset to align with this naming scheme would make it easier for others to adopt and extend this ruleset.

e.g. rule content-type could become rule json:api:1:sec4:content-type.

I'll submit a PR soon implementing this change.