added frameless demo example to AppSideNav showcase page

Author: didoo

showcase/app/templates/components/app-side-nav.hbs

@@ -522,4 +522,19 @@
       {{/each}}
     {{/let}}
   </Shw::Flex>
+</section>
+
+{{! For some reason, Ember tests don't play well with iframes (URL not found) so we can't take snapshots of these examples in Percy }}
+<section>
+
+  <Shw::Divider />
+
+  <Shw::Text::H2>Demo</Shw::Text::H2>
+
+  <Shw::Frame
+    @id="demo-full-app-frame-with-app-header-and-app-side-nav"
+    @src="/layouts/app-frame/frameless/demo-full-app-frame-with-app-header-and-app-side-nav"
+    @height="780"
+    @label="Full AppFrame with AppHeader & AppSideNav"
+  />
 </section>