Proposal: rename errata-related labels in all repositories

[pchampin]

All the labels in our multiple repositories have been inherited from other W3C repos, because many of them are common and have meaning outside the repos (e.g. labels for horizontal reviews).

Among those labels are 3 which are used by the errata management page creaed by @iherman (see example here): ErratumRaised, Errata and Editorial.

The latest is super confusing, because people tend to use it to mark other issues or PRs with it, while other labels should be used (e.g. spec:editorial). See example in https://w3c.github.io/json-ld-syntax/errata/

I propose to:

• rename these 3 labels with a prefix, following practice in other labels: errata:raised, errata:confirmed, errata:editorial;
• adapt @iherman 's code when (if) we adopt it, to use these tags instead of the original ones.

This would make our list of labels more consistent and, hopefully, easier to use.

[gkellogg]

Updating Ivan's display_errata to be more configurable to suit our needs might be an idea. Perhaps and errata.yml file might provide some configuration options, such as the labels to look for. Of course, another limitation of that system is that it seems to be one errata file per repository/specification, while IMO, we should have one for RDF and another for SPARQL. That may need something more customized for our particular needs.

While we're at it, two issue's I've raised would be nice for us to address: w3c/display_errata#19 on processing Markdown contained in comments used for creating errata, and w3c/display_errata#20 for being able to reference a particular erratum more easily.