Make Timeless compatible with MobileFrontend

I'm giving you some attention on Extension:MobileFrontend page and
want to promote skins which look nice on mobile.

https://www.mediawiki.org/wiki/Extension:MobileFrontend#Setup_a_skin

The targets are needed to ensure code is loaded by the skin when
operating in mobile mode so currently that wiki page is lying.
Please let it be true :)

Change-Id: Ie9ba6beec172f7b499ae347652318fe54d258e39

skin.json

@@ -17,6 +17,7 @@
 	},
 	"ResourceModules": {
 		"skins.timeless": {
+			"targets": [ "desktop", "mobile" ],
 			"position": "top",
 			"class": "ResourceLoaderSkinModule",
 			"styles": {
@@ -51,18 +52,21 @@
 			"@NOTE": "Remember to also update variables.less if you change the width cutoffs here. screen-misc.less and mobile.js may also need updating."
 		},
 		"skins.timeless.misc": {
+			"targets": [ "desktop", "mobile" ],
 			"position": "top",
 			"styles": [
 				"resources/screen-misc.less"
 			]
 		},
 		"skins.timeless.js": {
+			"targets": [ "desktop", "mobile" ],
 			"position": "bottom",
 			"scripts": [
 				"resources/main.js"
 			]
 		},
 		"skins.timeless.mobile": {
+			"targets": [ "desktop", "mobile" ],
 			"position": "bottom",
 			"scripts": [
 				"resources/libraries/jquery.mobile.custom.js",