* 'selectorWithVariant' => [CSS selector template, variables: {prefix} {name} {variant}],
* // List of variants that may be used for the image files
* 'variants' => [
- * [theme name] => [
+ * // This level of nesting can be omitted if you use the same images for every skin
+ * [skin name (or 'default')] => [
* [variant name] => [
* 'color' => [color string, e.g. '#ffff00'],
* 'global' => [boolean, if true, this variant is available
* ],
* // List of image files and their options
* 'images' => [
- * [theme name] => [
+ * // This level of nesting can be omitted if you use the same images for every skin
+ * [skin name (or 'default')] => [
* [icon name] => [
* 'file' => [file path string or array whose values are file path strings
* and whose keys are 'default', 'ltr', 'rtl', a single