Basic Packaging For SBT Projects - Underscores in filenames indicate directories

build.sbt

scalaVersion := "2.13.1"

enablePlugins(JavaAppPackaging)
maintainer := "foo@blah.com"

dockerBaseImage := "java:14"

project_anynamehere.sbt

// convention is plugins.sbt
addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.7.3")

project_build.properties

sbt.version=1.3.12

src_main_scala_foo.scala

object foo {
  def main(args: Array[String]): Unit = {
    println("Hello World!")
  }
}