Add F4SE plugin template

Create a minimal Fallout 4 F4SE/CommonLibF4 starter repo with build, packaging, install, and rename scripts, plus initial plugin source, headers, and xmake configuration.

scripts/package.ps1

@@ -0,0 +1,16 @@
+param(
+    [string]$OutputName = "F4SEPluginTemplate"
+)
+
+$ErrorActionPreference = "Stop"
+
+$root = Split-Path -Parent $PSScriptRoot
+$packageDir = Join-Path $root "package"
+$outFile = Join-Path $root "$OutputName.zip"
+
+if (Test-Path $outFile) {
+    Remove-Item $outFile -Force
+}
+
+Compress-Archive -Path (Join-Path $packageDir "*") -DestinationPath $outFile
+Write-Host "Created $outFile"