add publish scripts (PowerShell + bash) for single-command cross-platform builds

publish.ps1

@@ -0,0 +1,31 @@
+# Publish all targets for SRTto3Dsubtitles
+# Usage: ./publish.ps1
+
+$ErrorActionPreference = "Stop"
+
+$targets = @(
+    @{ Project = "ConvertSRTto3DASS.Cli";     Runtime = "linux-x64";    Name = "ConvertSRTto3DASS-linux-x64" },
+    @{ Project = "ConvertSRTto3DASS.Cli";     Runtime = "win-x64";      Name = "ConvertSRTto3DASS-win-x64.exe" },
+    @{ Project = "ConvertSRTto3DASS.Cli";     Runtime = "osx-x64";      Name = "ConvertSRTto3DASS-osx-x64" },
+    @{ Project = "ConvertSRTto3DASS.Cli";     Runtime = "osx-arm64";    Name = "ConvertSRTto3DASS-osx-arm64" },
+    @{ Project = "ConvertSRTto3DASS.Gui";     Runtime = "win-x64";      Name = "ConvertSRTto3DASS-GUI-Win-x64.exe" }
+)
+
+foreach ($t in $targets) {
+    Write-Host "Publishing $($t.Name)..." -ForegroundColor Cyan
+    dotnet publish $t.Project -c Release -r $t.Runtime `
+        --self-contained false `
+        -p:PublishSingleFile=true `
+        -p:IncludeNativeLibrariesForSelfExtract=true `
+        -p:OutputType=Exe `
+        -p:OutputPath="publish\$($t.Runtime)\"
+
+    $src = "publish\$($t.Runtime)\$($t.Project).exe"
+    $dst = "publish\$($t.Name)"
+    if (Test-Path $src) {
+        Move-Item $src $dst -Force
+        Write-Host "  -> $dst" -ForegroundColor Green
+    }
+}
+
+Write-Host "`nDone! Published files in publish/`n" -ForegroundColor Green