Add icon to external links (#2522)

* Change external links to use noreferrer

* Add external link styling

* Remove accidental double definition

docs/config.toml

@@ -15,6 +15,7 @@ index_format = "elasticlunr_json"
 [markdown]
 highlight_code = true
 highlight_theme = "kronuz"
+external_links_no_referrer = true
 #highlight_theme = "css"
 #highlight_themes_css = [
 #  { theme = "base16-ocean-dark", filename = "syntax-theme-dark.css" },

docs/sass/_base.scss

@@ -86,6 +86,14 @@ a {
       color: white;
     }
   }
+
+  &[rel~="noreferrer"] {
+    padding-right: 1em;
+    background-size: 14px;
+    background-image: $external-link-icon;
+    background-repeat: no-repeat;
+    background-position: center right;
+  }
 }
 
 pre {

docs/sass/_pattern.scss

@@ -1 +1,2 @@
 $grid-pattern: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='100' viewBox='0 0 100 100'%3E%3Cg fill-rule='evenodd'%3E%3Cg fill='%234b4b4b' fill-opacity='0.4'%3E%3Cpath opacity='.5' d='M96 95h4v1h-4v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4h-9v4h-1v-4H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15v-9H0v-1h15V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h9V0h1v15h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9h4v1h-4v9zm-1 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm9-10v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm9-10v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm9-10v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-10 0v-9h-9v9h9zm-9-10h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9zm10 0h9v-9h-9v9z'/%3E%3Cpath d='M6 5V0H5v5H0v1h5v94h1V6h94V5H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
+$external-link-icon: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="%23888888" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-external-link"><path d="M15 3h6v6"/><path d="M10 14 21 3"/><path d="M18 13v6a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h6"/></svg>');

docs/templates/index.html

@@ -18,8 +18,8 @@
                 <ul>
                     <li><a class="white" href="{{ get_url(path='@/documentation/_index.md') }}" class="nav-link">Docs</a></li>
                     <li><a class="white" href="{{ get_url(path='@/themes/_index.md') }}" class="nav-link">Themes</a></li>
-                    <li><a class="white" href="https://zola.discourse.group/" class="nav-link">Forum</a></li>
-                    <li><a class="white" href="https://github.com/getzola/zola" class="nav-link">GitHub</a></li>
+                    <li><a class="white" rel="noreferrer" href="https://zola.discourse.group/" class="nav-link">Forum</a></li>
+                    <li><a class="white" rel="noreferrer" href="https://github.com/getzola/zola" class="nav-link">GitHub</a></li>
                 </ul>
                 <div class="search-container">
                     <input id="search" type="search" placeholder="🔎 Search the docs">