deprecate torproject's RPM repository
Tpo's RPM repo has recently become unmaintained. When Nick asked why torproject's RPMs are superior to the distro packages no one spoke up  same on tor-relays .
Ondrej (former tpo rpm repo maintainer) said:
I'd think that since distro maintainers exist now, it might be better to use their packages.
To avoid having outdated relays around it might make sense to:
- remove https://www.torproject.org/docs/rpms.html.en
- announce the deprecation of the RPM repo on the blog (tell people to switch to the distro packages)
- create a last "update" that uninstalls tpo's RPM package and writes a log entry pointing to the blog post