Added Ruff linting rules.

.github/workflows/ruff.yml

@@ -0,0 +1,16 @@
+name: Ruff
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  ruff:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: astral-sh/ruff-action@v3
+        with:
+          src: ./named_arrays

README.md

@@ -2,7 +2,7 @@
 
 [![tests](https://github.com/sun-data/named-arrays/actions/workflows/tests.yml/badge.svg)](https://github.com/sun-data/named-arrays/actions/workflows/tests.yml)
 [![codecov](https://codecov.io/gh/sun-data/named-arrays/graph/badge.svg?token=1GhdcsgwO0)](https://codecov.io/gh/sun-data/named-arrays)
-[![Documentation Status](https://readthedocs.org/projects/named-arrays/badge/?version=latest)](https://named-arrays.readthedocs.io/en/latest/?badge=latest)
+[![Ruff](https://github.com/sun-data/named-arrays/actions/workflows/ruff.yml/badge.svg?branch=main)](https://github.com/sun-data/named-arrays/actions/workflows/ruff.yml)[![Documentation Status](https://readthedocs.org/projects/named-arrays/badge/?version=latest)](https://named-arrays.readthedocs.io/en/latest/?badge=latest)
 [![PyPI version](https://badge.fury.io/py/named-arrays.svg)](https://badge.fury.io/py/named-arrays)
 
 `named-arrays` is an implementation of a [named tensor](https://nlp.seas.harvard.edu/NamedTensor), which assigns names to each axis of an n-dimensional array such as a numpy array.