update the documentation to code-quote the params. plus, add the para…

…m type

lib/sass/script/functions.rb

@@ -2189,10 +2189,10 @@ def inspect(value)
     #   Return a decimal between 0 and 1, inclusive of 0, but not 1.
     #   @return [Sass::Script::Number] A decimal value.
     # @overload random($limit)
-    #   Return an integer between 1 and $limit inclusive.
-    #   @param $limit The maximum of the random integer to be returned, a positive integer.
+    #   Return an integer between 1 and `$limit` inclusive.
+    #   @param $limit [Sass::Script::Value::Number] The maximum of the random integer to be returned, a positive integer.
     #   @return [Sass::Script::Number] An integer.
-    #   @raise [ArgumentError] if the limit is not 1 or greater
+    #   @raise [ArgumentError] if the `$limit` is not 1 or greater
     def random(limit = nil)
       if limit
         assert_integer limit, "limit"