Add the API reference site, built on every PR and deployed to GitHub Pages on release

.github/dependabot.yml

@@ -40,6 +40,13 @@ updates:
       # runtime floor bumps grouped below, so they get a PR of their own.
       lint-tools:
         patterns: ["ruff", "mypy", "typos"]
+      # The docs group's site builder, the API reference plugin and parser, and
+      # the Markdown extensions mkdocs.yml enables (PER-16775). Zensical is
+      # alpha, so any release can change what the docs job's gate sees; a bump
+      # that breaks the site build gets a PR of its own rather than holding up
+      # the runtime floor bumps.
+      docs-tools:
+        patterns: ["zensical", "mkdocstrings*", "griffe*", "pymdown-extensions"]
       minor-and-patch:
         update-types: ["minor", "patch"]
     ignore:

.github/scripts/pytest.ini

@@ -3,7 +3,8 @@
 # configuration in pyproject.toml ([tool.pytest]), whose testpaths and
 # asyncio_mode belong to the SDK's suite. These tests need only pytest and the
 # standard library, though test_ci_checks.py also runs bash, jq, yq (mikefarah
-# v4) and shellcheck. They warn about nothing: any warning is an error.
+# v4) and shellcheck, and test_check_docs_build.py runs yq. They warn about
+# nothing: any warning is an error.
 [pytest]
 # strict_config, strict_markers, strict_xfail and strict_parametrization_ids.
 strict = true