added custom tab content class & demo in pages/UI/navbar

build/scss/_miscellaneous.scss

@@ -423,3 +423,20 @@ blockquote {
     }
   }
 }
+
+
+// Tab Custom Content
+
+.tab-custom-content {
+  border-top: $nav-tabs-border-width solid $nav-tabs-border-color;
+  margin-top: .5rem;
+  padding-top: .5rem;
+}
+
+.nav + .tab-custom-content {
+  border-top: none;
+  border-bottom: $nav-tabs-border-width solid $nav-tabs-border-color;
+  margin-top: 0;
+  margin-bottom: .5rem;
+  padding-bottom: .5rem;
+}

dist/css/adminlte.css

@@ -19193,6 +19193,20 @@ blockquote.quote-gray-dark h6 {
   color: #343a40;
 }
 
+.tab-custom-content {
+  border-top: 1px solid #dee2e6;
+  margin-top: .5rem;
+  padding-top: .5rem;
+}
+
+.nav + .tab-custom-content {
+  border-top: none;
+  border-bottom: 1px solid #dee2e6;
+  margin-top: 0;
+  margin-bottom: .5rem;
+  padding-bottom: .5rem;
+}
+
 @media print {
   .no-print, .main-sidebar,
   .main-header,