0.4.0

• The documentation projection writes different filenames. --kind docs now writes index.md
  rather than README.md, and domains/acd-routing.md rather than domains/acd.routing.md: a dot
  in a path segment makes a static file server read the name as having an extension, so every one
  of those pages was unservable behind GitLab Pages and an adopter carried a rename pass of their
  own. Committed output moves once; the links inside it move with it.
• Add forall: and exists: to the predicate language, quantifying an invariant over a List or
  a Map. A collection publishes its size as <path>.count, so no existing fact source changes to
  gain them, and one nobody observed evaluates to unknown rather than to the vacuous truth an
  empty one gives. Quantifying over anything that is not a collection is refused as
  type_mismatch.
• Add order_by: to a view, so a view named for a position says something about position.
  Generated conformance scenarios assert it on adjacent rows; a key the view does not project is
  refused, because a rank over a field nobody can read is a promise nothing can check.
• Add ess conform synthesize --target go, which writes a Go test package — the runner, a
  three-valued predicate evaluator and the suite — so an implementation in Go is held to the
  specification by go test. Previously conform run reached only the reference targets in this
  workspace, and an adopter's suite was regenerated on every model change and never executed.
• Add refs: to commands, outcomes, bindings and components, written provider:key, so a
  construct can name the ticket or incident that explains it. Conversion.because was the only
  prose field in the model, and everything else went into YAML comments no projection reads.
• Add ess generate --kind site: the documentation with frontmatter and a sidebar, for publishing
  as a static site.
• Print the refusals conform synthesize finds instead of counting them. A count says something is
  unchecked without saying what.
• Introduce ess-docs/1, an internal document representation between the model and the pages, with
  the markdown projection as one renderer of it. No output changes; the documentation of every
  example is pinned byte for byte and compared.