Run docs-build locally to catch errors before RTD

Author: hynek

tox.ini

@@ -5,7 +5,7 @@ env_list =
     mypy-pkg,
     py3{8,9,10,11,12,13,14}-{tests,mypy}
     py3{8,13}-tests-{colorama,be,rich},
-    docs-{sponsors,doctests},
+    docs-{sponsors,build,doctests},
     coverage-{combine,report}
 
 
@@ -58,6 +58,7 @@ commands = coverage report
 base_python = py313
 dependency_groups = docs
 commands =
+    # N.B. doctests is not a nitpicky as build -- we need to run both in CI!
     build: sphinx-build -n -T -W -b html -d {envtmpdir}/doctrees docs {posargs:docs/_build/}html
     doctests: sphinx-build -n -T -W -b doctest -d {envtmpdir}/doctrees docs {posargs:docs/_build/}html
     linkcheck: sphinx-build -W -b linkcheck -d {envtmpdir}/doctrees docs docs/_build/html