Fixed some minor css issue

**lib/internal/Magento/Framework/View/Test/Unit/Url/_files/sourceImport.css:**
+ `@import` statements should be at the top

**lib/web/css/docs/docs.css:**
+ Use `green` instead of `#green`

Author: arnoudhgz

lib/internal/Magento/Framework/View/Test/Unit/Url/_files/sourceImport.css

@@ -2,8 +2,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-body {background: url(body.gif);}
 @import url(../recursive.css);
-p {background: url(1.gif?param);}
 @import url("deep/recursive.css");
+body {background: url(body.gif);}
+p {background: url(1.gif?param);}
 h1 {background: url('../h1.gif#param');} h2 {background: url(../images/h2.gif?test);}