Added coding style modes to SimpleMDE (#3286)

* Added coding style modes to SimpleMDE

* Moved the CodeMirror addon from simplemd to codemirror directory

public/plugins/codemirror-5.17.0/mode/css/less_test.js

@@ -0,0 +1,54 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+(function() {
+  "use strict";
+
+  var mode = CodeMirror.getMode({indentUnit: 2}, "text/x-less");
+  function MT(name) { test.mode(name, mode, Array.prototype.slice.call(arguments, 1), "less"); }
+
+  MT("variable",
+     "[variable-2 @base]: [atom #f04615];",
+     "[qualifier .class] {",
+     "  [property width]: [variable percentage]([number 0.5]); [comment // returns `50%`]",
+     "  [property color]: [variable saturate]([variable-2 @base], [number 5%]);",
+     "}");
+
+  MT("amp",
+     "[qualifier .child], [qualifier .sibling] {",
+     "  [qualifier .parent] [atom &] {",
+     "    [property color]: [keyword black];",
+     "  }",
+     "  [atom &] + [atom &] {",
+     "    [property color]: [keyword red];",
+     "  }",
+     "}");
+
+  MT("mixin",
+     "[qualifier .mixin] ([variable dark]; [variable-2 @color]) {",
+     "  [property color]: [atom darken]([variable-2 @color], [number 10%]);",
+     "}",
+     "[qualifier .mixin] ([variable light]; [variable-2 @color]) {",
+     "  [property color]: [atom lighten]([variable-2 @color], [number 10%]);",
+     "}",
+     "[qualifier .mixin] ([variable-2 @_]; [variable-2 @color]) {",
+     "  [property display]: [atom block];",
+     "}",
+     "[variable-2 @switch]: [variable light];",
+     "[qualifier .class] {",
+     "  [qualifier .mixin]([variable-2 @switch]; [atom #888]);",
+     "}");
+
+  MT("nest",
+     "[qualifier .one] {",
+     "  [def @media] ([property width]: [number 400px]) {",
+     "    [property font-size]: [number 1.2em];",
+     "    [def @media] [attribute print] [keyword and] [property color] {",
+     "      [property color]: [keyword blue];",
+     "    }",
+     "  }",
+     "}");
+
+
+  MT("interpolation", ".@{[variable foo]} { [property font-weight]: [atom bold]; }");
+})();