Resolve "Add lambda param to addon install"

Closes #55 (closed)

Changes the BotBuilder#install function to add an optional configuration lambda

suspend fun <A : BotAddon> install(provider: BotAddonProvider<A>, config: suspend A.() -> Unit = {}) {
  val addon = provider.provide()
  config(addon)
  addon.installTo(this)
  _addons[addon.name] = addon
}