Add link in Readme to underlying Electron issue preventing macOS builds from being produced on Windows machines

Author: yoDon

README.md

@@ -150,7 +150,7 @@ The end result should be an electron app under your __/bin/desktop__ folder.
 There is a React/Typescript/MobX starter kit at https://github.com/yoDon/Electron.NET-React-Typescript-MobX
 
 ### Note
-> macOS builds on Windows are currently not supported, because the build just hangs, but I'm not sure why. The macOS builds works on Linux/macOS however.
+> macOS builds can't be created on Windows machines because they require symlinks that aren't supported on Windows (per [this Electron issue](https://github.com/electron-userland/electron-packager/issues/71)). macOS builds can be produced on either Linux or macOS machines.
 
 # Working with this Repo