Fix homepage link. (#54)

Author: csyonghe

_includes/header.html

@@ -1,10 +1,10 @@
 <div class='header'>
   <div class="container">
     <div class="logo">
-      <a href="{{ site.baseurl }}"><img width="{{ site.logo.desktop_width }}" height="{{ site.logo.desktop_height }}" alt="{{ site.title }}" src="{{ site.logo.desktop | relative_url }}" /></a>
+      <a href="/"><img width="{{ site.logo.desktop_width }}" height="{{ site.logo.desktop_height }}" alt="{{ site.title }}" src="{{ site.logo.desktop | relative_url }}" /></a>
     </div>
     <div class="logo-mobile">
-      <a href="{{ site.baseurl }}"><img width="{{ site.logo.mobile_width }}" height="{{ site.logo.mobile_height }}" alt="{{ site.title }}" src="{{ site.logo.mobile | relative_url }}" /></a>
+      <a href="/"><img width="{{ site.logo.mobile_width }}" height="{{ site.logo.mobile_height }}" alt="{{ site.title }}" src="{{ site.logo.mobile | relative_url }}" /></a>
     </div>
     {% include main-menu.html %}
     {% include hamburger.html %}