Add an example Docker call for MSYS2 based shells

Author: Vampire

README.md

@@ -275,6 +275,9 @@ You can also limit the font weights that will be created with the `-w / --weight
 
 # or via a docker container (creates the family name 'Fira Code cv01 cv02 cv06 cv31 onum ss01 ss03 ss04 zero')
 docker run --rm -v "${PWD}":/opt tonsky/firacode:latest ./script/build.sh -f "cv01,cv02,cv06,ss01,zero,onum,ss03,ss04,cv31" -n "features"
+
+# in Git Bash from Git for Windows, or any other MSYS2 based shell, you might need to disable path conversion
+MSYS2_ARG_CONV_EXCL="*" docker run --rm -v "${PWD}":/opt tonsky/firacode:latest ./script/build.sh -f "ss02,ss03,ss04,ss05,ss06,ss07"
 ```
 
 ### Credits