Add windows tips in documentation

Author: moltenform

README.md

@@ -470,6 +470,14 @@ sudo yum install imagemagick pdfinfo
 brew install imagemagick xpdf
 ```
 
+## Windows
+
+- The script should work fine in cygwin.
+- If you are using msys/git for windows, and the script exits with a 'file not found' error,
+- try running `export MSYS_NO_PATHCONV=1`
+- and `export MSYS2_ARG_CONV_EXCL="*"`
+- and then running again.
+
 ## Clone using git
 ```
 git clone https://github.com/tavinus/pdfScale.git