add windows install instructions

Author: cbrake

windows.md

@@ -0,0 +1,27 @@
+# Using GitPLM on Windows
+
+(the following was tested on Windows 10. Feel free to open a PR if you have
+better ideas or have tested on other versions.)
+
+The GitPLM binaries are not signed, so some effort is required to get past all
+the Windows security checks. If someone would like to contribute a process to
+sign the binaries for Windows that is not too arduous, that would be
+appreciated.
+
+1. Download the appropriate Windows
+   [release](https://github.com/git-plm/gitplm/releases). For most people, this
+   will be the `windows-x86_64`. If you have a newer ARM based (such as the new
+   Surface), you may need the `windows-arm64` release.
+1. extact the downloaded zip file
+1. Windows may complain about the program because it is from an Unknown
+   publisher. It appears that programs
+   [written in Go are often flagged](https://github.com/microsoft/go/issues/1255).
+   If Windows pops upa Virus & threat protection dialog, click on the "Severe"
+   text, and select "Allow on device", then "Start actions".
+1. Double click on the `gitplm` binary in windows Explorer. Windows may show a
+   Windows protected your PC dialog. Click on the "More info" link and select
+   "Run Anyway". gitplm should now and ask you to enter a directory containing
+   partmaster csv files.
+1. cp the `gitplm` binary to the `C:\bin` directory.
+1. add `C:\bin` to your system path (System properties->Environment variables)
+1. now in powershell, you should be able to run `gitplm`.