Add black format check

This will provide a useful ci check before users can merge.

.github/workflows/pythonpackage.yml

@@ -21,6 +21,9 @@ jobs:
           python -m pip install --upgrade pip
           pip install -r requirements-dev.txt
           poetry install
+      - name: Format check with black
+        run: |
+          make format
       - name: Typecheck with mypy
         run: |
           make typecheck

Makefile

@@ -1,5 +1,7 @@
 test:
 	pytest --cov-report term-missing --cov=rich tests/ -vv
+format:
+	black --check rich
 typecheck:
 	mypy -p rich --ignore-missing-imports --warn-unreachable
 typecheck-report: