add a .ruff.toml and a ruff.yml workflow

.github/workflows/ruff.yml

@@ -0,0 +1,19 @@
+on:
+  pull_request:
+  push:
+    branches:
+      - master 
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: chartboost/ruff-action@v1
+      - run: | 
+        ruff check .
+        ruff fix .
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: 'style fixes by ruff'
+
+

.ruff.toml

@@ -0,0 +1,8 @@
+line-length = 120
+indent-width = 4
+
+fixable = ["ALL"]
+unfixable = []
+
+[format]
+line-ending = "lf"