Add pyproject.toml, poetry.lock and install_jigsaw.py.

In principle, this should be able to reproduce the functionality
of the current setup.py into a poetry environment.

install_jigsaw.py

@@ -0,0 +1,26 @@
+from pathlib import Path
+import shutil
+import subprocess
+
+def run():
+    src_parent = Path(__file__).parent.resolve()
+    jigsaw_src_dir = src_parent / "external/jigsaw"
+    cmake_build_dir = jigsaw_src_dir / "build"
+    cmake_build_dir.mkdir(exist_ok=True)
+    subprocess.run(
+        [
+            "cmake",
+            '..',
+            "-DCMAKE_BUILD_TYPE=Release",
+            "-DCMAKE_INSTALL_PREFIX=."
+        ],
+        cwd=cmake_build_dir
+        )
+    subprocess.run(["make", f"-j4"], cwd=cmake_build_dir)
+    subprocess.run(["make", f"-j4", "install"], cwd=cmake_build_dir)
+    exesrc_path = cmake_build_dir / "bin"
+    libsrc_path = cmake_build_dir / "lib"
+    exedst_path = src_parent / "jigsawpy/_bin"
+    libdst_path = src_parent / "jigsawpy/_lib"
+    shutil.copytree(exesrc_path, exedst_path)
+    shutil.copytree(libsrc_path, libdst_path)

pyproject.toml

@@ -0,0 +1,34 @@
+[tool.poetry]
+name = "jigsawpy"
+version = "1.0.0"
+description = "Python interface for the JIGSAW meshing library."
+authors = ["Darren Engwirda <[email protected]>"]
+homepage = "https://github.com/dengwirda/"
+keywords = ["Mesh-generation", "Delaunay", "Voronoi"]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Operating System :: OS Independent",
+    "Intended Audience :: Science/Research",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: C++",
+    "Topic :: Scientific/Engineering",
+    "Topic :: Scientific/Engineering :: Mathematics",
+    "Topic :: Scientific/Engineering :: Physics",
+    "Topic :: Scientific/Engineering :: Visualization"
+]
+
+[tool.poetry.dependencies]
+python = ">=3.9.0,<3.13"
+numpy = "^1.25.2"
+scipy = "^1.11.1"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"
+
+[tool.poetry.scripts]
+install-jigsaw = 'install_jigsaw:run'
+
+[tool.poetry.urls]
+"Github" = "https://github.com/dengwirda/"