fix realatie paths in links

Author: marco66colombo

_includes/nav.html

@@ -12,12 +12,19 @@
 			<ul class="navbar-nav">
 				{% for navitem in site.navbar.links %}
 				<li class="nav-item">
+					{% assign is_mailto = navitem.link contains 'mailto:' %}
+					{% assign is_external = navitem.link contains '://' %}
+					{% assign is_absolute_internal = navitem.link | slice: 0, 1 %}
 					{% if navitem.autoscroll %}
 					{% if page.title != 'Home' %}
 					<a class="nav-link" href="{{ site.baseurl }}/{{ navitem.link }}">{{ navitem.name }}</a>
 					{% else %}
 					<a class="nav-link" href="{{ navitem.link }}">{{ navitem.name }}</a>
 					{% endif %}
+					{% elsif is_mailto or is_external %}
+					<a class="nav-link" href="{{ navitem.link }}">{{ navitem.name }}</a>
+					{% elsif is_absolute_internal == '/' %}
+					<a class="nav-link" href="{{ navitem.link | relative_url }}">{{ navitem.name }}</a>
 					{% else %}
 					<a class="nav-link" href="{{ navitem.link }}">{{ navitem.name }}</a>
 					{% endif %}