Make description of Show Desktop and Minimize All applets consistent

Use the same wording structure for both given they appear next to each
other in the alternatives switcher

applets/showdesktop/package/contents/ui/main.qml

@@ -34,7 +34,7 @@ QtObject {
     Plasmoid.onActivated: showdesktop.showingDesktop = !showdesktop.showingDesktop
     Plasmoid.icon: plasmoid.configuration.icon
     Plasmoid.title: i18n("Show Desktop")
-    Plasmoid.toolTipSubText: i18n("Show the Plasma desktop")
+    Plasmoid.toolTipSubText: i18n("Show the desktop by moving windows aside")
     Plasmoid.backgroundHints: PlasmaCore.Types.NoBackground
 
     // QtObject has no default property

applets/showdesktop/package/metadata.desktop

@@ -36,7 +36,7 @@ Name[uk]=Показати стільницю
 Name[x-test]=xxShow Desktopxx
 Name[zh_CN]=显示桌面
 Name[zh_TW]=顯示桌面
-Comment=Show the Plasma desktop
+Comment=Shows the desktop by moving windows aside
 Comment[ast]=Amuesa l'escritoriu de Plasma
 Comment[az]=Plasma İş Masasını göstərmək
 Comment[ca]=Mostra l'escriptori Plasma