design improvement

Clean.ps1

@@ -0,0 +1,11 @@
+function Remove($path) {
+    if (Test-Path $path) {
+        Remove-Item $path -Recurse -Force
+    } else {
+        Write-Host "Path don't exist: $path"
+    }
+}
+
+Remove("obj")
+Remove(".vs")
+Remove("*.csproj.user")