1.Added install support for openEuler 20.03LTS and 22.03LTS with YARO(Yet Another Repository for openEuler).
2.Fixed the bug when install restic on CentOS 8, now it can be installed directly through EPEL.
3.Updated some text descriptions.
Putting some make-up on the install.sh script"
- This relies on the `/etc/os-release` file which is present on all modern distributions that you are currently supporting. More info on: https://www.freedesktop.org/software/systemd/man/os-release.html
- I've taken the liberty of including a warning message for CentOS 8 / CloudLinux 8
- I've also derived `SERVER_OS` from the proper strings. I suggest you end up using a variable directly from `/etc/os-release` instead, tough, as it's just extra-fluff right now, and it seems you are using it just for statistics purposes
- I have also switched to using `printf >&2` to output the messages to `stderr` instead of `stdout` because they are technically warnings
