Add editorconfig

.editorconfig

@@ -0,0 +1,15 @@
+# https://EditorConfig.org
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 4
+
+[*.lock]
+indent_size = unset
+
+[*.{nix,html,json}]
+indent_size = 2