bug#55815: [PATCH] bindat: Improve str, strz documentation

[Eli Zaretskii <eliz@gnu.org>]

> Cc: monnier@iro.umontreal.ca
> Date: Sun, 5 Jun 2022 22:22:01 -0400
> From: Richard Hansen <rhansen@rhansen.org>
> 
>   @item str @var{len}
> -String of bytes of length @var{len}.
> +String of length @var{len}.

I think it is better to say

  Unibyte string that is @var{len} bytes long.

>   @item strz &optional @var{len}
> -Zero-terminated string of bytes, can be of arbitrary length or in a fixed-size
> -field with length @var{len}.
> +If @var{len} is not provided: Variable-length null-terminated string.

Same here: it is better to mention the unibyte-ness up front, since
it's important.

> +If @var{len} is provided: @code{strz} behaves the same as @code{str}
> +with one difference. When unpacking, the first zero byte (null
                      ^^
Our conventions are to leave two spaces between sentences.

Also, for consistency, I suggest to use "null byte" everywhere, to
avoid potential confusion of non-native English speakers.

Thanks.