feat: add workflow to produce templated standard project docs

[fredbi]

Is your feature request related to a problem? Please describe.

Standard project documentation is essentially duplicated across repos and it has to (cannot easily use links).

• CODE_OF_CONDUCT
• LICENSE
• SECURITY
• CONTRIBUTING
• STYLE
• DCO
• MAINTAINERS

This extends to config files:

• .golangci.yml
• dependabot.yaml

NOTE: for .cliff.toml, it is no longer required to maintain it locally (can be fetched remotely when cutting a release)

Describe the solution you'd like

Add a new workflow to produce templated standard project docs and synchronize accross repos

The current repo would become the central source of truth for much of the documentation and configuration boiler plate.

But NOT: README, NOTICE (not standardized).

Proposed workflow:

• maintain templates in ci-workflows/docs, ci-workflows/config
• change in templates trigger an event (webhook)
• in target repos (all go-openapi repos), the webhook trigger the doc update locally (PR + auto-merge)
  • regen config & docs with local specifics (e.g. version number, links, idiosyncratic section ...)
  • create PR
  • auto-merge

Describe alternatives you've considered

• CODE_OF_CONDUCT can be moved to go-openapi/.github
• all other documents can't easily be moved there
• for .golangci-lint.yml, attempted a change to the linter that would allow it to download remote config, but it's a lot more complex than expected

Additional context