[design] improve default controls

Author: zombieFox

package-lock.json

@@ -1,6 +1,6 @@
 {
 "name": "nighttab",
-"version": "4.19.4",
+"version": "4.20.0",
 "description": "A neutral new tab page accented with a chosen colour. Customise the layout, style, background and bookmarks in nightTab.",
 "main": "index.js",
 "scripts":{

package.json

@@ -127,3 +127,11 @@
 .icon-reorder:before{
 content:"\e901";
 }
+
+.icon-undo:before{
+content:"\e902";
+}
+
+.icon-redo:before{
+content:"\e903";
+}