Documentation fix. No code changed.
README-FIRST.txt — the first file in the archive — still described Traymetry
as a private test build handed out to friends, and said there was no public
update channel. Both were out of date. It is rewritten for anyone downloading
the release, and it now exists in English (README-FIRST.txt) and Russian
(README-FIRST.ru.txt).
Verifying the download
SHA256SUMS.txt covers all four other assets. The updater checks
Traymetry-update-manifest.txt against Traymetry-update-manifest.sig with
the public key compiled into the executable before it replaces anything.