Flesh out pyproject.toml to allow properly installing

Mostly because I'd like to be able to install it with uv, so it's
entirely for selfish reasons.

git_tidy.py

@@ -1,21 +1,26 @@
 #!/usr/bin/env python3
-
+# Copyright 2023-2025 James Smith
 # git-tidy is free software: you can redistribute it and/or modify it under the terms of the GNU
 # General Public License as published by the Free Software Foundation, either version 3 of the
 # License, or (at your option) any later version.
-
 # git-tidy is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 # the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 # Public License for more details.
-
 # You should have received a copy of the GNU General Public License along with git-tidy. If not, see
 # <https://www.gnu.org/licenses/>.
 """git-tidy utility."""
 
+import argparse
 import subprocess
 import sys
 from typing import List, Tuple, Union
 
+try:
+    from importlib.metadata import version
+except ImportError:
+    # Python < 3.8
+    from importlib_metadata import version
+
 common_default_branches = [
     "main",
     "master",
@@ -127,6 +132,10 @@ def get_default_branch() -> str:
 
 def main():
     """Main function."""
+    parser = argparse.ArgumentParser(description="A time-saving device for a developer using git.")
+    parser.add_argument("--version", action="version", version=f"git-tidy {version('git-tidy-python')}")
+    parser.parse_args()
+    
     default_branch = get_default_branch()
     print(f"Switching to {default_branch}")
     run(["git", "checkout", default_branch])

pyproject.toml

@@ -1,6 +1,45 @@
-[tool.black]
+[build-system]
+requires = ["setuptools>=45", "setuptools-scm[toml]>=6.2", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "git-tidy-python"
+dynamic = ["version"]
+description = "A time-saving device for a developer using git."
+authors = [
+    {name = "James Smith"}
+]
+readme = "README.md"
+license = {text = "GPL-3.0-or-later"}
+requires-python = ">=3.8"
+dependencies = []
+keywords = ["git", "cli", "developer-tools", "automation", "branch-management"]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Environment :: Console",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.6",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Topic :: Software Development :: Version Control :: Git",
+    "Topic :: Utilities"
+]
+
+[project.scripts]
+git-tidy = "git_tidy:main"
+
+[tool.setuptools]
+py-modules = ["git_tidy"]
+
+[tool.ruff]
 line-length = 120
-include = '\.pyi?$'
 exclude ='''
 /(
 	| \.git
@@ -11,3 +50,5 @@ exclude ='''
 [tool.isort]
 profile = "black"
 line_length = 120
+
+[tool.setuptools_scm]