Blacken and isort code, add pre-commit and CI linting

.github/workflows/python-lint.yml

@@ -0,0 +1,24 @@
+name: Python lint
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v4
+      with:
+        python-version: "3.11"
+    - uses: isort/isort-action@master
+      with:
+        sortPaths: "./reactbot"
+    - uses: psf/black@stable
+      with:
+        src: "./reactbot"
+    - name: pre-commit
+      run: |
+        pip install pre-commit
+        pre-commit run -av trailing-whitespace
+        pre-commit run -av end-of-file-fixer
+        pre-commit run -av check-added-large-files