Readme: update for demo metas changes
Readme: update for demo metas changes

gamedevsam/haxeflixel.com,IBwWG/haxeflixel.com,IBwWG/haxeflixel.com,gamedevsam/haxeflixel.com,gamedevsam/haxeflixel.com,IBwWG/haxeflixel.com