v0.12.37: @newsroom.writer: A policy for every skill, without a name

At the owner's request, a person named in A policy for every skill is no longer named: they had not yet read the article or agreed to be credited. The article, its graph and the release notes say "a friend". So that the site's version pages do not repeat the name, publish.py gains folded history: sources listed in admin/build/history-folds.json, each with its reason, are replayed with their current text at every past commit, so the article publishes as one version. The repository's git history is unchanged and keeps every version.