add wallpaper config

components/composite/WallpaperList.qml

@@ -19,7 +19,7 @@ ListView {
     implicitHeight: 90
     model: FolderListModel {
         nameFilters: ["*.jpg"]
-        folder: `${Paths.home}/Wallpapers`
+        folder: `file://${Paths.expandTilde(Config.wallpaper.directory)}`
         showDirs: false
     }
     delegate: Item {

config/Config.qml

@@ -7,6 +7,7 @@ Singleton {
     id: root
 
     readonly property alias powermenu: adapter.powermenu
+    readonly property alias wallpaper: adapter.wallpaper
 
     FileView {
         path: `${Paths.config}/shell.json`
@@ -19,6 +20,7 @@ Singleton {
             id: adapter
 
             property var powermenu: PowerMenu {}
+            property var wallpaper: Wallpaper {}
         }
     }
 
@@ -30,4 +32,8 @@ Singleton {
         property string text
         property string command
     }
+
+    component Wallpaper: JsonObject {
+        property string directory
+    }
 }