styler's LLM edition

Improvements

Rewrite single-clause case statements to be assignments (h/t 🤖)

# before
case foo |> Bar.baz() |> Bop.boop() do
  {:ok, widget} ->
    x = y
    wodget(widget)
end

# after
{:ok, widget} = foo |> Bar.baz() |> Bop.boop()
x = y
wodget(widget)