Add black to pre-commit and requirements.

Follow on PR to reformat existing files

.pre-commit-config.yaml

@@ -0,0 +1,27 @@
+repos:
+- repo: local
+  hooks:
+  - id: flake8
+    name: flake8
+    entry: flake8
+    language: system
+    types: [python]
+  - id: mypy
+    name: mypy
+    entry: mypy
+    language: system
+    types: [python]
+  - id: black
+    name: black
+    description: "Black: The uncompromising Python code formatter"
+    entry: black --line-length=100
+    language: python
+    require_serial: true
+    types: [python]
+    additional_dependencies: [black==23.1.0]
+  - id: pytest
+    name: pytest
+    entry: coverage run -m pytest --typeguard-packages=strictly_typed_pandas,tests
+    language: system
+    types: [python]
+    pass_filenames: false