   If `level` is an integer, that's the indentation appended
   to line breaks whenever they occur. If the level is `:cursor`,
   the current position of the "cursor" in the document becomes
-  the nesting.
+  the nesting. If the level is `:reset`, it is set back to 0.
 
   `mode` can be `:always`, which means nesting always happen,
   or `:break`, which means nesting only happens inside a group


  def nest(doc, :cursor, mode) when is_doc(doc) and mode in [:always, :break] do
    doc_nest(doc, :cursor, mode)
  end

  def nest(doc, 0, _mode) when is_doc(doc) do

    quote do: {:doc_cons, unquote(left), unquote(right)}
  end

  @typep doc_nest :: {:doc_nest, t, :cursor | :reset | non_neg_integer, :always | :break}
  defmacrop doc_nest(doc, indent, always_or_break) do
    quote do: {:doc_nest, unquote(doc), unquote(indent), unquote(always_or_break)}
  end
