Return index of undecodable element in dynamic.list DecodeError path

[johtso]

stdlib/src/gleam/dynamic.gleam

Lines 320 to 329 in d8f046a

	pub fn list(
	of decoder_type: fn(Dynamic) -> Result(inner, DecodeErrors),
	) -> Decoder(List(inner)) {
	fn(dynamic) {
	use list <- result.try(shallow_list(dynamic))
	list
	|> list.try_map(decoder_type)
	|> map_errors(push_path(_, "*"))
	}
	}

I think it would be nice to return the index of the offending element instead of just "*"

I'm new to gleam, but I had a little play around trying to implement this and could open a pull request..

[lpil]

Fab idea! Thank you