Add README content, add example/demo script

Fix setting license in pyproject.toml correctly

Point to main script in pyproject to run CLI

README.md

@@ -0,0 +1,39 @@
+# Nix Background Upgrade
+Upgrade NixOS system (and/or home-manager) in the background, with notification support.
+
+**Early stages of development, subject to change and likely not working at the current stage.**
+
+## Install
+Clone the repository and install with pip (or preferred Python packaging system):
+
+```bash
+git clone https://git.xenia.me.uk/pixelifytica/nix-background-upgrade.git
+python3 -m pip install ./nix-background-upgrade
+```
+
+### For development
+Project uses [Poetry](https://python-poetry.org/ "Poetry: Python packaging and dependency management tool") to manage dependencies.
+
+Install Poetry (see [documentation](https://python-poetry.org/docs/#installation) for more details), for example using `pipx`:
+
+```bash
+pipx install poetry
+```
+
+Then install project using `poetry`:
+
+```bash
+poetry install
+```
+
+Python code is formatted using [black](https://pypi.org/project/black/ "The uncompromising code formatter") and [isort](https://pypi.org/project/isort/ "A Python utility / library to sort Python imports").
+
+#### `pre-commit`
+[pre-commit](https://pre-commit.com/ "A framework for managing and maintaining multi-language pre-commit hooks") is used to ensure formatting of new/changed files. Install pre-commit hooks with:
+
+```bash
+pre-commit install --install-hooks
+```
+
+### Nix Flake
+Project provides a Nix `flake.nix` to get up and running quickly.

pyproject.toml

@@ -4,9 +4,13 @@ version = "0.1.0"
 description = "Upgrade NixOS system (and/or home-manager) in the background, with notification support"
 authors = ["Evie Litherland-Smith <evie@xenia.me.uk>"]
 readme = "README.md"
-license = "LICENSE"
+license = "MIT"
+repository = "https://git.xenia.me.uk/pixelifytica/nix-background-upgrade"
 packages = [{include = "nix_background_upgrade", from = "src"}]
 
+[tool.poetry.scripts]
+nbu = 'nix_background_upgrade.main:main'
+
 [tool.poetry.dependencies]
 python = "^3.9"
 notify-py = "^0.3.0"

src/nix_background_upgrade/main.py

@@ -0,0 +1,17 @@
+from .notification import create_notification
+
+
+def main(*args, **kwargs) -> None:
+    """
+    Sends a test notification to check everything is working
+
+    :returns: None
+    """
+    notification = create_notification()
+    notification.message = "This is a test notification"
+    notification.send()
+    return
+
+
+if __name__ == "__main__":
+    main()

src/nix_background_upgrade/notification.py

@@ -0,0 +1,16 @@
+from pathlib import Path
+
+from notifypy import Notify
+
+
+def create_notification() -> Notify:
+    """
+    Create notification class
+
+    :returns: Notify class with custom defaults
+    """
+    return Notify(
+        default_notification_title="Nix Background Update",
+        default_notification_message="Message from Nix process",
+        default_notification_icon=Path(__file__).parent / "./nix-snowflake.png",
+    )