Fix depth problem

_includes/meta.html

@@ -4,7 +4,7 @@
 {% assign base = '' %}
 {% assign depth = page.url | split: '/' | size | minus: 1 %}
 <meta property='page:depth' content='{{depth}}'>
-{% if depth == 1 %}{% assign base = '.' %}
+{% if depth >= 1 %}{% assign base = '.' %}
 {% elsif depth == 2 %}{% assign base = '..' %}
 {% elsif depth == 3 %}{% assign base = '../..' %}
 {% elsif depth == 4 %}{% assign base = '../../..' %}{% endif %}