Small typo correction for trek documentation

[Andras Farkas <deepbluemistake%gmail.com@localhost>]

I was skimming through trek.txt (since it seems interesting) and I
noticed a small typo.
Diff attached.
SHA512 (trekdiff) =
2fff2337ee8283eaa54cf0de7ea1f75ba4c3935ca852b095f4d83cb21b15b9ae844790d82b9bda565d9eca53606da7a4e093e46774c74f87ef9560bca8262b29
Diff made on NetBSD 9.2

Attachment: trekdiff
Description: Binary data