Added meta viewport tag to fix issue BonsaiDen#171

Author: ZhangYiJiang

garden.jade

@@ -4,6 +4,7 @@ html(lang=language)
     title #{title}
     meta(charset='utf-8')
     meta(name='description', content=description)
+    meta(name='viewport', content='width=device-width, initial-scale=1')
 
     - if (language === baseLanguage)
       link(rel='stylesheet', href='style/garden.css', media='all')