add pre-commit config (#29)

.pre-commit-config.yaml

@@ -0,0 +1,14 @@
+repos:
+  - repo: https://github.com/psf/black
+    rev: 21.11b1
+    hooks:
+      - id: black
+        language_version: python3.9
+
+ci:
+    autofix_commit_msg: '[pre-commit.ci] auto fixes from pre-commit.com hooks'
+    autofix_prs: true
+    autoupdate_commit_msg: '[pre-commit.ci] pre-commit autoupdate'
+    autoupdate_schedule: weekly
+    skip: []
+    submodules: false

pyproject.toml

@@ -4,7 +4,7 @@ include = '\.pyi?$'
 skip-magic-trailing-comma = true
 experimental-string-processing = true
 
-exclude = '''
+force-exclude = '''
 /(
     \.git
   | \.mypy_cache