Add node modules and new code for release (#39)

Co-authored-by: tbarnes94 <tbarnes94@users.noreply.github.com>

node_modules/cssstyle/lib/properties/background.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var shorthandSetter = require('../parsers').shorthandSetter;
+var shorthandGetter = require('../parsers').shorthandGetter;
+
+var shorthand_for = {
+  'background-color': require('./backgroundColor'),
+  'background-image': require('./backgroundImage'),
+  'background-repeat': require('./backgroundRepeat'),
+  'background-attachment': require('./backgroundAttachment'),
+  'background-position': require('./backgroundPosition'),
+};
+
+module.exports.definition = {
+  set: shorthandSetter('background', shorthand_for),
+  get: shorthandGetter('background', shorthand_for),
+  enumerable: true,
+  configurable: true,
+};