Test with Nox

Adds a `noxfile.py` that enables easier local testing across multiple Python versions. It's configued to use `uv` to speed up the generation of the test virtual environments.

noxfile.py

@@ -0,0 +1,77 @@
+import argparse
+
+import nox
+import yaml
+
+with open("./.github/workflows/main.yaml") as f:
+    workflow = yaml.safe_load(f)
+
+python_versions = workflow['jobs']['test']['strategy']['matrix']['python-version']
+# pydantic_versions = workflow['jobs']['test']['strategy']['matrix']['pydantic-version']
+
+nox.options.default_venv_backend = "uv"
+
+@nox.session(python=python_versions)
+@nox.parametrize("pydantic", ["<2", ">=2"])
+def tests(session: nox.Session, pydantic: str):
+    """Run py.test"""
+    session.install("-r", "dev-requirements.txt")
+    session.install(".")
+    session.install(f"pydantic{pydantic}")
+    session.run("pytest", "--verbose", "--pdb")
+
+
+@nox.session
+def pre_commit(session: nox.Session):
+    """Run pre-commit"""
+    session.install("pre-commit")
+    session.run("pre-commit", "run")
+
+
+@nox.session
+def docs(session: nox.Session):
+    """
+    Build docs using Sphinx. 
+    
+    Add --live (nox -s docs -- --live) to run a live server
+    Add --clean to clean docs directory first
+    """
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--clean", action="store_true", help="Clean the build directory first")
+    parser.add_argument("--live", action="store_true", help="Run a live updating server for docs")
+    args, posargs = parser.parse_known_args(session.posargs)
+
+    session.install("-r", "dev-requirements.txt")
+    session.install(".")
+
+    session.chdir("docs")
+    session.install("-r", "requirements.txt")
+    session.install("sphinx-autobuild")
+
+    BUILDDIR = "_build"
+
+    if args.clean:
+        session.run(
+            "rm", "-rf", f"{BUILDDIR}/*"
+        )
+
+    if args.live:
+        session.run(
+            "sphinx-autobuild",
+            "-b",
+            "dirhtml",
+            "source/",
+            "_build/dirhtml/"
+        )
+    else:
+        session.run(
+            "sphinx-build",
+            "-b",
+            "dirhtml",
+            "-d",
+            f"{BUILDDIR}/doctrees",
+            "source/dirhtml",
+        )
+
+
+nox.options.sessions = ["tests"]