added 1909 dockerfile

docker/Dockerfile.windows.1909

@@ -0,0 +1,20 @@
+# escape=`
+
+FROM mcr.microsoft.com/windows/servercore:1909 AS git
+SHELL ["powershell.exe", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+
+RUN [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 ; `
+    Invoke-WebRequest -UseBasicParsing https://github.com/git-for-windows/git/releases/download/v2.21.0.windows.1/MinGit-2.21.0-64-bit.zip -OutFile git.zip; `
+    Expand-Archive git.zip -DestinationPath C:\git;
+
+FROM mcr.microsoft.com/powershell:nanoserver-1909
+COPY --from=git /git /git
+
+ADD windows/* /bin/
+
+# https://github.com/PowerShell/PowerShell/issues/6211#issuecomment-367477137
+USER ContainerAdministrator
+RUN setx /M PATH "%PATH%;C:\Program Files\PowerShell"
+
+SHELL ["pwsh", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
+CMD [ "pwsh", "C:\\bin\\clone.ps1" ]