Add editorconfig.

.editorconfig

@@ -0,0 +1,16 @@
+# see https://editorconfig.org/
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_style = space
+indent_size = 4
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.{yml,yaml}]
+indent_size = 2

.vscode/extensions.json

@@ -3,6 +3,7 @@
       "ms-python.vscode-pylance",
       "ms-python.python",
       "ms-python.debugpy",
-    "charliermarsh.ruff"
+      "charliermarsh.ruff",
+      "editorconfig.editorconfig"
   ]
 }