Make Error struct accessible outside the crate

[acanthite1855]

Because the Error is not accessible from outside the crate I cannot implement From (either manually or via thiserrors #[from] and the like).
Without this I'm basically forced to to_string the error and wrap that with my own error type.

Not that I need more than just a string to output the description of the error, but it's a little bit annoying that I have to do it manually, while #[from] could do everything for me.

[Xuanwo]

Thanks a lot!