#139 added release signing for windows

doc/sign-log4net-libraries.ps1

@@ -0,0 +1,15 @@
+# see https://infra.apache.org/release-signing#openpgp-ascii-detach-sig
+$DidSomething = $false
+$Files = Get-Item $PSScriptRoot/../build/artifacts/* -Include *log4net*.nupkg, *log4net*.zip
+foreach ($File in $Files)
+{
+  $DidSomething = $true
+  "signing: $File"
+  gpg --armor --output "$($File.FullName).asc" --detach-sig $File.FullName
+}
+
+if (!$DidSomething)
+{
+  Write-Error "No log4net artifacts found - are you sure you're in the right directory?"
+  exit 2
+}