Add nav-external class for external links

Author: agriyakhetarpal

layouts/partials/footer.html

@@ -16,7 +16,7 @@
       <div class="footer-column">
         {{- range .links }}
         <div class="footer-item">
-          <a href="{{ .link }}">
+          <a href="{{ .link }}"{{ if .is_external }} class="nav-external" target="_blank" rel="noopener"{{ end }}>
             {{ .text }}
           </a>
         </div>

layouts/partials/navbar.html

@@ -40,14 +40,14 @@
 
           <div class="navbar-dropdown">
             {{- range .sublinks }}
-            <a href="{{ .url }}" class="navbar-item">
+            <a href="{{ .url }}" class="navbar-item{{ if .is_external }} nav-external{{ end }}"{{ if .is_external }} target="_blank" rel="noopener"{{ end }}>
               {{ .title | safeHTML }}
             </a>
             {{- end }}
           </div>
         </div>
         {{- else }}
-        <a href="{{ .url }}" class="navbar-item">
+        <a href="{{ .url }}" class="navbar-item{{ if .is_external }} nav-external{{ end }}"{{ if .is_external }} target="_blank" rel="noopener"{{ end }}>
           {{ .title | safeHTML }}
         </a>
         {{- end }}