improved tooling (isort and flake8 with "black" compatibility)

.flake8

@@ -1,4 +1,4 @@
 [flake8]
 max-line-length = 80
-select = C,E,F,I,W,B,B950
-extend-ignore = E203, E501
+extend-select = B950
+extend-ignore = E203,E501,E701

.isort.cfg

@@ -0,0 +1,3 @@
+[settings]
+profile = "black"
+line_length = 80

.vscode/settings.json

@@ -1,20 +1,20 @@
 {
     "python.languageServer": "Pylance",
-    "editor.formatOnSave": true,
     "[python]": {
-        "editor.defaultFormatter": "ms-python.black-formatter"
-    },
+        "editor.formatOnSave": true,
+        "editor.defaultFormatter": "ms-python.black-formatter",
         "editor.codeActionsOnSave": {
             "source.organizeImports": "explicit"
         },
+    },
     "git.closeDiffOnOperation": true,
     "python.analysis.typeCheckingMode": "basic",
     "python.analysis.diagnosticMode": "workspace",
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true,
     "python.testing.pytestArgs": [
         "--import-mode=importlib"
     ],
-    "python.testing.unittestEnabled": false,
-    "python.testing.pytestEnabled": true,
     "black-formatter.importStrategy": "fromEnvironment",
     "flake8.importStrategy": "fromEnvironment",
 }