Resolve docs version/release automatically

Author: snejus

docs/conf.py

@@ -1,6 +1,16 @@
 import datetime as dt
 import os
+import re
 import sys
+from pathlib import Path
+
+MATCH_VERSION_LINE = re.compile(r"version = \W((\d+\.\d+)\.\d.*?)\W").fullmatch
+
+pyproject = Path(__file__).parent.parent / "pyproject.toml"
+version_line_match = next(
+    filter(None, map(MATCH_VERSION_LINE, pyproject.read_text().splitlines()))
+)
+release, version = version_line_match.groups()
 
 sys.path.insert(0, os.path.abspath(".."))
 
@@ -17,9 +27,6 @@
 project = "Confuse"
 copyright = "2012-{}, Adrian Sampson & contributors".format(dt.date.today().year)
 
-version = "2.1"
-release = "2.1.1"
-
 exclude_patterns = ["_build"]
 
 pygments_style = "sphinx"