v2.5.0

A page whose body was built from template tags described itself with their
source. # {{ site.title }} over {{ site.description }} shipped an
og:description reading "site.description" and an anchor at #site-title,
while the page itself rendered the real title and the real description right
underneath. The build stayed green through both, and the only symptom was a link
preview nobody looks at until someone shares the page.

Added

• A description filter emits <meta name="description">, escaped.
  {{ page | description(site) }} (Liquid: {{ page | description: site }})
  reads the same chain og and jsonld do — front matter description, then
  the page's auto-excerpt, then site.description — so the three cannot
  disagree, and emits nothing when none of them is set. Poops renders with
  autoescape off, so a layout writing that tag by hand ships the front matter
  verbatim: one " in a sentence closes the attribute and truncates the
  description to the words before it, silently, on a green build. Poops' own
  v2.4.0 post described itself as A for exactly that reason. Escaping now
  happens in one named place rather than in every layout that remembers.

Fixed

• page.excerpt is taken after the template engine has run. A first
  paragraph written as {{ site.description }}, or supplied by an
  {% include %} ahead of the prose, is resolved before the text is taken, so
  the description is the one a reader gets. The excerpt now reads the rendered
  body's first <p> rather than guessing at the markdown source — headings,
  comments, code fences and tables are skipped because they are not paragraphs,
  and link text comes through without its URL. When nothing usable resolves the
  excerpt is empty and og/jsonld/<meta name="description"> fall through to
  site.description — the old behaviour was to strip the braces and ship
  site.description as a literal string, which then beat the very value it was
  standing in front of. Only pages whose first paragraph is a tag pay for the
  extra render.

  A collection item is read without a page context, so its excerpt is empty in
  that case rather than resolved; listings and feeds fall back to the item's
  description. The item's own page still resolves it.

• Heading ids are slugged from the rendered heading. # {{ site.title }},
  # {{ page.title }} and # My Site now all anchor at #my-site, so swapping
  which variable feeds a heading no longer remints every bookmarked URL. The
  toc filter slugs from the same text, so its links still land.

Full Changelog: v2.4.0...v2.5.0