feat(menu): support open an entry in new tab

closes https://github.com/CaiJimmy/hugo-theme-stack/issues/230

exampleSite/config.yaml

@@ -142,6 +142,9 @@ menu:
           url: /
           weight: -100
           pre: home
+          params:
+            ### For demonstration purpose, the home link will be open in a new tab
+            newTab: true
 
 related:
     includeNewer: true
@@ -157,7 +160,7 @@ related:
 markup:
     tableOfContents:
         endLevel: 4
-        ordered: true
+        ordered: false
         startLevel: 2
     highlight:
         noClasses: false

layouts/partials/sidebar/left.html

@@ -39,7 +39,7 @@
         {{ $active := or (eq $currentPage.Title .Name) (or ($currentPage.HasMenuCurrent "main" .) ($currentPage.IsMenuCurrent "main" .)) }}
 
         <li {{ if $active }} class='current' {{ end }}>
-            <a href='{{ .URL }}'>
+            <a href='{{ .URL }}' {{ if eq .Params.newTab true }}target="_blank"{{ end }}>
                 {{ if .Pre }}
                     {{ partial "helper/icon" .Pre }}
                 {{ end }}