feat: show header & footer only if requested (support for quiqqer/app)

Related: #12

index.html

@@ -28,15 +28,17 @@
 {template_event name="quiqqer::template::body::begin" Template=$Template}
 
 {* <!--top bar / navigation--> *}
-{fetch template="template/topBar.html"
-    navBackground=$navBackground
-    MegaMenu=$MegaMenu
-    logoUrl=$logoUrl
-    logoText=$logoText
-    Site=$Site
-    altLogoTargetUrl=$altLogoTargetUrl
-    logoUrlAlt=$logoUrlAlt
-}
+{if $Template->getAttribute('template-header')}
+    {fetch template="template/topBar.html"
+        navBackground=$navBackground
+        MegaMenu=$MegaMenu
+        logoUrl=$logoUrl
+        logoText=$logoText
+        Site=$Site
+        altLogoTargetUrl=$altLogoTargetUrl
+        logoUrlAlt=$logoUrlAlt
+    }
+{/if}
 
 {template_event name="quiqqer::template::body::afterMenu" Template=$Template}