[tor-qa] Tor Browser 10.5.8 is ready for testing

[Matthew Finkel]

Hello!

We are happy to announce the first Tor Browser 10.5.8 release candidate
for wider testing. Packages can be found at:

https://people.torproject.org/~sysrqb/builds/10.5.8-build1/

Tor Browser 10.5.8 updates Firefox to 78.15.0esr.

The full changelog since Tor Browser 10.5.7 is:
 * Windows + OS X + Linux
    * Update Firefox to 78.15.0esr

Please be aware, we are planning a build2 therefore assume this is not
the final release build.