Add sbt-dependency-graph-sugar plugin.
Use scalajs's jsdeps to include bootstrap and jquery js files.
Make source maps load on server.

Very hacky implementation.

Copied from https://github.com/scala-js/scala-js/blob/5a385e36346793edba4fb45682ae23578d761b9e/sbt-plugin/src/main/scala/scala/scalajs/sbtplugin/ScalaJSPluginInternal.scala#L191-L193