Updated Contrib (markdown)

Contrib.md

@@ -25,6 +25,17 @@ This works on Docker for Mac as well as a linux system running docker.  I have t
 
 No modification of my editor settings was needed for this to integrate (I checked Vim through syntastic and VSCode).
 
+### Windows Git-bash Docker wrapper script
+ 
+[@pletnes says](https://github.com/koalaman/shellcheck/issues/1978):
+
+>I'd like to have a documented how-to for beginners on windows. Personally, I use docker in git-bash. I don't know if this is a "common setup". I came up with this first attempt, which could go into the wiki
+
+```sh
+#!/bin/bash
+exec docker run --rm -v "$(cygpath -aw .):/mnt" koalaman/shellcheck:stable "$@"
+```
+
 ### Emacs auto-fix script
 
 By [@matthewpersico](https://github.com/matthewpersico)