Mill, Cask, Scala.js with shared js code between server and client

Ported from https://github.com/jrudolph/akka-http-scala-js-websocket-chat

Now using:

• Mill build tool
• Cask web server
• Scala.js example client with shared code between server and client.
• Vuejs gui nuxt integrated in mill build
• VS Code Vetur configured. https://marketplace.visualstudio.com/items?itemName=octref.vetur

Currently needs initial npm install in vuegui folder. Set up for development, use: mill -w server.runBackground

http://localhost:8384/htm/

Cask file serving has a nasty hack to be able to serve a default page required by vuejs routing. This would be handled by reverseproxy (eg nginx) in production scenario.