add note on installing wix to build windows installer
@@ -28,6 +28,8 @@ The Sparrow binaries can be built from source using
`./gradlew jpackage`
+Note that to build the Windows installer, you will need to install [WiX](https://github.com/wixtoolset/wix3/releases).
+
When updating to the latest HEAD
`git pull --recurse-submodules`
