Adding setting of wallpaper

requirements.ps1

@@ -28,7 +28,11 @@ param (
   [Alias('no-fonts')]
   [switch]$NoFonts,
   [Alias('only-fonts')]
-  [switch]$OnlyFonts
+  [switch]$OnlyFonts,
+  [Alias('no-wallpaper')]
+  [switch]$NoWallpaper,
+  [Alias('only-wallpaper')]
+  [switch]$OnlyWallpaper
 )
 
 if ($Help)
@@ -74,6 +78,7 @@ $Flags = [ordered]@{
   PipEnabled = -not $NoPip
   NpmEnabled = -not $NoNpm
   FontsEnabled = -not $NoFonts
+  WallpaperEnabled = -not $NoWallpaper
 }
 
 function Reset-Flags
@@ -119,6 +124,11 @@ if ($OnlyFonts)
   Reset-Flags
   $Flags.FontsEnabled = $true
 }
+if ($OnlyWallpaper)
+{
+  Reset-Flags
+  $Flags.WallpaperEnabled = $true
+}
 
 Write-Host "These providers are enabled:"
 foreach ($key in $Flags.Keys)
@@ -238,5 +248,21 @@ if ($Flags.FontsEnabled)
   Remove-Item ~\fonts -Force -Recurse| Out-Null
 }
 
+if ($Flags.WallpaperEnabled)
+{
+  Write-Divider
+  Write-Host "Setting Wallpaper"
+  Add-Type @"
+using System;
+using System.Runtime.InteropServices;
+public class Wallpaper {
+    [DllImport("user32.dll", SetLastError = true)]
+    public static extern bool SystemParametersInfo(
+        int uAction, int uParam, string lpvParam, int fuWinIni);
+}
+"@ -ErrorAction SilentlyContinue
+
+  [Wallpaper]::SystemParametersInfo(20, 0, "$HOME\wallpaper.png", 0x03) | Out-Null
+}
 Write-Divider
 Write-Host "Done!"