added back to top style & demo inside widget

build/scss/_layout.scss

@@ -3,6 +3,10 @@
  * ------------
  */
 
+html {
+  scroll-behavior: smooth;
+}
+
 html,
 body,
 .wrapper {

build/scss/_miscellaneous.scss

@@ -353,3 +353,14 @@
     }
   }
 }
+
+// Scroll To Top
+.back-to-top {
+  bottom: 1.25rem;
+  position: fixed;
+  right: 1.25rem;
+
+  &:focus {
+    box-shadow: none;
+  }
+}

dist/css/adminlte.css

@@ -9654,6 +9654,10 @@ a.text-dark:hover, a.text-dark:focus {
  * Core: Layout
  * ------------
  */
+html {
+  scroll-behavior: smooth;
+}
+
 html,
 body,
 .wrapper {
@@ -16637,6 +16641,16 @@ html.maximized-card {
   right: 0;
 }
 
+.back-to-top {
+  bottom: 1.25rem;
+  position: fixed;
+  right: 1.25rem;
+}
+
+.back-to-top:focus {
+  box-shadow: none;
+}
+
 /*
  * Misc: Print
  * -----------

pages/widgets.html

@@ -2123,6 +2123,10 @@
       </div><!-- /.container-fluid -->
     </section>
     <!-- /.content -->
+
+    <a id="back-to-top" href="#" class="btn btn-primary back-to-top" role="button" aria-label="Scroll to top">
+      <i class="fas fa-chevron-up"></i>
+    </a>
   </div>
   <!-- /.content-wrapper -->