Sidebar: match header margins and layout spacings

sidebar/package/contents/ui/CategoriesPage.qml

@@ -43,6 +43,7 @@ Kirigami.ScrollablePage {
                 left: parent.left
                 right: parent.right
             }
+            spacing: Math.round(Kirigami.Units.smallSpacing/2) // Match margins
 
             QQC2.ToolButton {
                 id: showIntroPageButton

sidebar/package/contents/ui/SubCategoryPage.qml

@@ -40,6 +40,7 @@ Kirigami.ScrollablePage {
 
         contentItem: RowLayout {
             anchors.fill: parent
+            spacing: Math.round(Kirigami.Units.smallSpacing/2) // Match margins
 
             // Show a back Button when only one column is visible
             QQC2.ToolButton {