Feature description
It seems that there's no file named /etc/os-release in termux.
All of the linux distros have one with them, so having one for termux is no great deal, and it's one step forward for termux to become a better linux emulator. You know, some guys might depend on release file to learn what distro is being currently use, and those alternatives which check which package manager is present, may give a false alert that ubuntu/debian is being used and not termux, since apt-get is found on termux too.
Additional information
https://www.freedesktop.org/software/systemd/man/os-release.html