Differentiate between page titles and menu titles

_includes/head.html

@@ -2,7 +2,7 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width initial-scale=1" />
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
-    <title>{% if page.title %}{{ page.title }}{% else %}{{ site.title }}{% endif %}</title>
+    <title>{% if page.title %}PCjs: {{ page.title }}{% else %}{{ site.title }}{% endif %}</title>
     <meta name="description" content="{{ site.description }}">
     <link href="https://fonts.googleapis.com/css?family=Open+Sans" rel="stylesheet" type="text/css">
     <link rel="stylesheet" href="{{ "/css/main.css" | prepend: site.baseurl }}">

_includes/header.html

@@ -16,8 +16,8 @@
       <div class="trigger">
         {% assign sorted_pages = site.pages | sort:"menu_order" %}
         {% for page in sorted_pages %}
-          {% if page.title and page.menu_order %}
-          <a class="page-link" href="{{ page.url | prepend: site.baseurl }}">{{ page.title }}</a>
+          {% if page.menu_title %}
+          <a class="page-link" href="{{ page.url | prepend: site.baseurl }}">{{ page.menu_title }}</a>
           {% endif %}
         {% endfor %}
       </div>