update /layouts/header.html template with new CSS rules.

This commit makes the header (site's name and logo) a link which points back to
the site's "/" (I.E. Home page/route). It, also, centralises the header and the
navigation menu (in the header). This is so the header doesn't look weird when
viewed on a mobile phone.

I removed the <hr> at the bottom of the file because the site has enough styling
applied to it to make the <hr> look out of place now. I can clearly
denote/identify where the site's (front-end) header and footer stops and starts.

templates/layouts/header.html

@@ -110,33 +110,50 @@
     </div>
     {% endif %}
 
-    <div class="fe-site-header">
+    <a class="fe-site-header"
+       title="Click to view the site's home page"
+       href="/">
         {% ifequal system-data.first.enable-site-logo 1 %}
         <img alt="{{system-data.first.site-name}}"
 	     src="/images/site-logo.png">
         {% endifequal %}
         <h1>{{system-data.first.site-name}}</h1>
-    </div>
+    </a>
 
-    <div>
     <nav>
         {% for page in system-data.last.first %}
         {% ifequal page.enable-nav-menu 1 %}
         {% if page.slug == "login" %}
-	    <a href="/{{page.slug}}">{{page.title}}</a>
+        <a href="/{{page.slug}}"
+           title="Click to view the Login page">
+            {{page.title}}
+        </a>
         {% elif page.slug == "home" %}
-	    <a href="/">{{page.title}}</a>
+        <a href="/"
+           title="Click to view the site's home page">
+            {{page.title}}
+        </a>
         {% elif page.slug == "archive" %}
-	    <a href="/{{page.slug}}">{{page.title}}</a>
+        <a href="/{{page.slug}}"
+           title="Click to view the site's Archive index">
+            {{page.title}}
+        </a>
         {% elif page.slug == "pages" %}
-	    <a href="/{{page.slug}}">{{page.title}}</a>
+        <a href="/{{page.slug}}"
+           title="Click to view the site's Pages index">
+            {{page.title}}
+        </a>
         {% elif page.slug == "sign-up" %}
-	    <a href="/{{page.slug}}">{{page.title}}</a>
+        <a href="/{{page.slug}}"
+           title="Click to create an account with this website">
+            {{page.title}}
+        </a>
         {% else %}
-	    <a href="/view/page/{{page.slug}}">{{page.title}}</a>
+        <a href="/view/page/{{page.slug}}"
+           title="Click to view '{{page.title}}'">
+            {{page.title}}
+        </a>
         {% endif %}
         {% endifequal %}
         {% endfor %}
     </nav>
-    </div>
-    <hr>