[Feature Request] Change first message about missing XML configuration

[retropassdev]

When app is first started, Settings page is shown with a message:

"Couldn't locate RetroPass configuration file.
Make sure a valid RetroPass.xml is in the root of your removable storage."

Users often think there is something wrong with the setup and don't know what to do next. Change the message to something more descriptive or maybe a link to github readme.