update title

src/_includes/layout/core.njk

@@ -21,7 +21,7 @@
       {{css | cssmin | safe}}
     </style>
     {% if title %}
-      <title>{{ site.title }} - {{ title }}</title>
+      <title>{{ title }}</title>
     {% else %}
       <title>{{ site.title }}</title>
     {% endif %}