Distillery looks for a rel folder in the project root to find out how it should build the release. In its simplest form, this folder only needs to have a config.exs file.
To create a typical release configuration, we will run the Mix release.init task in the project root:
$ mix release.initAn example config file has been placed in rel/config.exs, review it,make edits as needed/desired, and then run `mix release` to build the release
The generated configuration file starts by loading any plugin that we may have in the rel/plugins folder and then uses the Mix.Releases.Config module so it can use its macros. Because we're setting :default_release as :default, if we just do mix release (that is, we didn't choose any
