Fix the relative links on sidebar tabs.

Author: cotes2020

_includes/sidebar.html

@@ -31,15 +31,15 @@
   <ul class="nav flex-column">
     <!-- home -->
     <li class="nav-item d-flex justify-content-center {% if page.layout == 'home' %}active{% endif %}">
-      <a href="/" class="nav-link d-flex justify-content-center align-items-center w-100">
+      <a href="{{ '/' | relative_url }}" class="nav-link d-flex justify-content-center align-items-center w-100">
         <i class="fa-fw fas fa-home ml-xl-3 mr-xl-3 unloaded"></i>
         <span>{{ "HOME" }}</span>
       </a>
     </li>
     <!-- the real tabs -->
     {% for tab in site.tabs %}
     <li class="nav-item d-flex justify-content-center {% if tab.url == page.url %}active{% endif %}">
-      <a href="{{ tab.url }}" class="nav-link d-flex justify-content-center align-items-center w-100">
+      <a href="{{ tab.url | relative_url }}" class="nav-link d-flex justify-content-center align-items-center w-100">
         <i class="fa-fw {{ tab.icon }} ml-xl-3 mr-xl-3 unloaded"></i>
         <span>{{ tab.title | upcase }}</span>
       </a>