Add LAUNCHER_SHA256 description

Co-authored-by: Jamie Thompson <[email protected]>

Author: hamzaremmal

pkgs/README.md

@@ -7,6 +7,7 @@ Official support for Chocolatey started by the release of Scala 3.6.0
 > The `scala.nuspec` and `chocolateyInstall.ps1` files needs to be rewritten by changing the following placeholders:
 > - @LAUNCHER_VERSION@ : Placeholder for the current scala version to deploy
 > - @LAUNCHER_URL@     : Placeholder for the URL to the windows zip released on GitHub
+> - @LAUNCHER_SHA256@  : Placeholder for the SHA256 of the msi file released on GitHub
 
 ## Important information