feat(poetry): add pyproject.toml for project dependencies and config

- Introduce `pyproject.toml` to define project metadata and dependencies
- Configure `poetry` for package management and build system
- Specify required libraries and script entry point

Signed-off-by: Max P. <Mail@MPassarello.de>

pyproject.toml

@@ -0,0 +1,22 @@
+[tool.poetry]
+name = "repocat"
+version = "0.1.0"
+description = ""
+authors = ["Max P. <Mail@MPassarello.de>"]
+readme = "README.md"
+packages = [{ include = "repocat", from = "src" }]
+
+[tool.poetry.dependencies]
+python = ">=3.12"
+rich = "^14.0.0"
+typer = { extras = ["all"], version = "^0.15.3" }
+pyyaml = "^6.0.2"
+pydantic = "^2.11.4"
+zstandard = "^0.23.0"
+
+[tool.poetry.scripts]
+repocat = "repocat.__main__:main"
+
+[build-system]
+requires = ["poetry-core>=2.0.0"]
+build-backend = "poetry.core.masonry.api"