Support keys for the `doi-link-valid` error rule

[mfisher87]

Proposal

Currently, I can control the doi-link-valid error rule by adjusting the level of all errors that fall under that rule. I only want to handle cases where I'm trying to link to a webpage on DOI.org, not to an actual DOI (#828).

Rowan was providing some support and found that this rule doesn't support keys:

mystmd/packages/myst-transforms/src/links/doi.ts

Line 29 in 23bf540

ruleId: RuleId.doiLinkValid,

I'd like to use a key that corresponds exactly to the URL I'm using in my code, e.g.:

  error_rules:
    - rule: "doi-link-valid"
      key: "https://doi.org/the-identifier/what-is-a-doi/"
      severity: "warn"

i.e. I would prefer that the key not look like doi:the-identifier/what-is-a-doi/!

Additional notes

Thanks, y'all are awesome ;)

[rowanc1]

I think that #2492 should fix this!