Merge branch 'master' into canary

layouts/partials/sidebar/left.html

@@ -27,7 +27,7 @@
     </header>
 
     {{- with .Site.Menus.social -}}
-        <ol class="social-menu">
+        <ol class="menu-social">
             {{ range . }}
                 <li>
                     <a 
@@ -54,7 +54,7 @@
             <a href='{{ .URL }}' {{ if eq .Params.newTab true }}target="_blank"{{ end }}>
                 {{ $icon := default .Pre .Params.Icon }}
                 {{ if .Pre }}
-                    {{ warnf "Menu item [%s] is using [pre] field to set icon, please use [params.icon] instead.\nMore information: https://docs.stack.jimmycai.com/configuration/custom-menu.html" .URL }}
+                    {{ warnf "Menu item [%s] is using [pre] field to set icon, please use [params.icon] instead.\nMore information: https://stack.jimmycai.com/config/menu" .URL }}
                 {{ end }}
                 {{ with $icon }}
                     {{ partial "helper/icon" . }}