chore(editorconfig): add an .editorconfig

.editorconfig

@@ -0,0 +1,13 @@
+# EditorConfig from https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# All files
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true