Add link to latest Morse Windows installer

[stephendade]

Now that Morse is integrated (and working!) with Appveyor, the final stage is to grab the built installers and put them somewhere...

My suggestion would be to after each successful Appveyor build, upload the installers to Github releases, like what is described in https://www.appveyor.com/docs/deployment/github/, though I've not been around long enough to know the release process for Morse.

Somewhat related - the Appveyor builds for Morse appear to be hidden or private. I've been using the https://ci.appveyor.com/project/morse-simulator/morse URL without success. Are the admins able to check if the build results are public or if I've got the wrong URL?