Initialize the project

- describe how a local develop environment can be set up
- we use poetry to manage the project
  => add pyproject.toml and poetry.lock files
- add a package for the source code
  => "src" layout structure to ensure that pytest runs the tests
     against a packaged version installed in a virtual environment
     and not the *.py files in the project directory
     (Source: https://hynek.me/articles/testing-packaging/)
- ignore poetry's artifacts in git

pyproject.toml

@@ -0,0 +1,46 @@
+[tool.poetry]
+
+name = "lalib"
+version = "0.4.2.dev0"
+
+authors = [
+    "Alexander Hess <alexander@webartifex.biz>",
+]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Intended Audience :: Developers",
+    "Intended Audience :: Education",
+    "Intended Audience :: Science/Research",
+    "License :: OSI Approved :: MIT License",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+]
+description = "A Python library to study linear algebra"
+license = "MIT"
+readme = "README.md"
+
+homepage = "https://github.com/webartifex/lalib"
+repository = "https://github.com/webartifex/lalib"
+
+
+[tool.poetry.dependencies]
+
+python = "^3.9"
+
+
+[tool.poetry.group.dev.dependencies]
+
+
+
+[tool.poetry.urls]
+
+"Issues Tracker" = "https://github.com/webartifex/lalib/issues"
+
+
+
+[build-system]
+
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"