config + whitespace: add .prettierrc; apply consistent indentation (space@2ea)

.editorconfig

@@ -5,6 +5,5 @@ root = true
 charset = utf-8
 end_of_line = lf
 insert_final_newline = true
-indent_style = tab
-indent_size = 4
-tab_width = 4
+indent_style = space
+indent_size = 2

.prettierrc

@@ -0,0 +1,10 @@
+{
+  "trailingComma": "es5",
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": true,
+  "bracketSpacing": true,
+  "bracketSameLine": true,
+  "arrowParens": "always"
+}