Rename powershell command

scripts/Windows/Software/osu!/Manage.ps1

@@ -5,7 +5,7 @@ $null = New-Module {
     $softwareName = "osu!";
     $genericConfigName = "osu!.User.cfg";
 
-    function Invoke-BackupOsu([Context] $context) {
+    function Backup-Osu([Context] $context) {
         $archive = $context.SoftwareArchive($softwareName);
         $context.Backup($path, $archive, @("-i@`"$PSScriptRoot/include.txt`""));
         & 7z rn "$archive" "osu!.$env:USERNAME.cfg" $genericConfigName;