improve: black and flake8 configs

Author: samedii

.flake8

@@ -0,0 +1,4 @@
+[flake8]
+max-line-length = 80
+select = C,E,F,W,B,B950
+extend-ignore = E203, E501

pyproject.toml

@@ -30,3 +30,25 @@ black = "^20.8b1"
 [build-system]
 requires = ["poetry-core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.black]
+line-length = 88
+target-version = ['py38']
+include = '\.pyi?$'
+exclude = '''
+
+(
+  /(
+      \.eggs
+    | \.git
+    | \.hg
+    | \.mypy_cache
+    | \.tox
+    | \.venv
+    | _build
+    | buck-out
+    | build
+    | dist
+  )/
+)
+'''