Elixir - best practices:

1. add vscode formatter
2. https://hexdocs.pm/elixir/patterns-and-guards.html
3. ex_doc tool (see https://github.com/elixir-lang/ex_doc)
4. static analysis tool called dialyzer (http://erlang.org/doc/man/dialyzer.html) - requires typespecs (https://hexdocs.pm/elixir/typespecs.html)