Grant's self-correction on Erlixir compile time checks

erlixir_types.md

• The compiler verifies the arity and name of calls within a module.
• The compiler cannot verify the same across modules as you can dynamically load new code.
• You can use a tool called dialyzer to add compile time type checks manually. Tutorial: http://learningelixir.joekain.com/elixir-type-safety/
• Erlixir = is a matching operator and not your usual assignment. Some fun examples along with the pin operator: https://elixirschool.com/lessons/basics/pattern-matching/
• By extension defining your own record types and doing judicious pattern matching can help provide some runtime type safety. (In that things explode instead of doing nonsense)