docs: use git version

Move the Sphinx configuration out of conf.py and pass it as
command line arguments so that the version and release fields
are derived from PATCHWORK_VERSION (which comes from git
describe). Display the version in the docs title.

Signed-off-by: Robin Jarry <robin@jarry.cc>

Author: rjarry

Makefile

@@ -52,7 +52,16 @@ docs:
 		$(PYTHON) -m venv docs/.venv && \
 		docs/.venv/bin/pip install -q -r docs/requirements.txt; \
 	fi
-	docs/.venv/bin/sphinx-build -b html docs docs/_build
+	docs/.venv/bin/sphinx-build --builder html --isolated \
+		-Dextensions=reno.sphinxext \
+		-Dproject=Patchwork \
+		-Dcopyright="The Patchwork Contributors" \
+		-Dauthor="The Patchwork Contributors" \
+		-Dversion="$(PATCHWORK_VERSION)" \
+		-Drelease="$(PATCHWORK_VERSION)" \
+		-Dexclude_patterns=_build,.venv \
+		-Dhtml_theme=sphinx_rtd_theme \
+		docs docs/_build
 
 import_reviser ?= github.com/incu6us/goimports-reviser/v3@v3.12.6
 import_reviser_flags ?= -rm-unused -project-name github.com/getpatchwork/patchwork

docs/conf.py

@@ -3,8 +3,8 @@
 ..
 .. SPDX-License-Identifier: GPL-2.0-or-later
 
-Patchwork
-=========
+Patchwork -- |release|
+======================
 
 .. toctree::
    :maxdepth: 2