[COMMITTED] contrib.texi: Updates

[Collin Funk]

Hi Andreas,

Andreas K. Hüttel <dilfridge@gentoo.org> writes:

>  @item
>  Stephen R. van den Berg for contributing a highly-optimized
>  @code{strstr} function.
> @@ -77,6 +83,9 @@ Stephen R. van den Berg for contributing a highly-optimized
>  Ond@v{r}ej B@'ilka for contributing optimized string routines for x64 and various
>  fixes.

Can we use UTF-8 in the manual? It would be nice to not have to use
these Texinfo commands for accents [1].

> +@item
> +Padraig Brady for various contributions.
> +

And it would be nice to write Pádraig here with the accent.

Note that we already have some UTF-8 that seeminly snuck into the manual
a few years ago, 'git blame' says 2022:

    $ grep -P -n '[^\x00-\x7F]' manual/*.texi
    manual/intro.texi:618:@c Instead of having to define each instance of “id”, we'd have a
    manual/intro.texi:619:@c general pattern governing all such “id”s, wherein race:id would
    manual/intro.texi:621:@c safe, whereas ro:id would indicate “id” is expected to be read-only,
    manual/math.texi:2261:@code{2^32−1} (inclusive), which is twice the range of @code{rand} and

Specifically the last line uses MINUS SIGN U+2212. The rest are in
comments so don't matter much.

Collin

[1] https://www.gnu.org/software/texinfo/manual/texinfo/html_node/Inserting-Accents.html