Improve web app deployment instructions
We need to make sure that we have documentation (can be XWiki pages, md file in Git, etc. all properly linked with each other) to cover the following topic:
- How to install Jetty
- How to deploy MRL web application
- The configuration (e.g. port number) that we are using in dev and prod
- How to start/stop the server
@gibello if you have any other topic that you think should be include in the deployment doc please add it as a comment. I'll create another issue for documenting endpoints.