Typo in faq4.html

Hi,

In faq4.html, the link to OpenBSD's firmware directory is not working.
Indeed it is http://firmware.openbsd.org instead of
http://firmware.openbsd.org/firmware/ as shown in fw_update(8)'s
manpage.
Here is a proposed diff.

All the best,
Robin

Index: faq4.html
===================================================================
RCS file: /cvs/www/faq/faq4.html,v
retrieving revision 1.555
diff -u -p -r1.555 faq4.html
--- faq4.html 16 Oct 2023 12:52:20 -0000 1.555
+++ faq4.html 4 Nov 2023 13:02:43 -0000
@@ -512,7 +512,7 @@ a bootable install image with the necess
If you don't have an existing OpenBSD system with internet access, use
another computer to download the appropriate file from
<!-- XXX needs https -->
-<a href="http://firmware.openbsd.org">firmware.openbsd.org</a> and put
+<a href="http://firmware.openbsd.org/firmware/">firmware.openbsd.org/firmware/</a> and put
it on a USB drive that's readable by OpenBSD.
Then, on the OpenBSD machine,
<a href="https://man.openbsd.org/mount">mount(8)</a> the drive and use