shortcode: add highlight options support to code_sample

Author: Caesarsage

layouts/shortcodes/code_sample.html

@@ -1,5 +1,6 @@
 {{ $p := .Page }}
 {{ $file := .Get "file" }}
+{{ $opts := .Get "options" | default "" }}
 {{ $codelang := .Get "language" | default (path.Ext $file | strings.TrimPrefix ".") }}
 {{ $fileDir := path.Split $file }}
 {{ $bundlePath := path.Join .Page.File.Dir $fileDir.Dir }}
@@ -34,7 +35,7 @@
     {{- end -}}
     </div>
     <div class="includecode" id="{{ $file | anchorize }}">
-    {{- highlight . $codelang "" -}}
+       {{- highlight . $codelang $opts -}}
     </div>
 </div>
 {{- end -}}