Please document Tor Browser's javascript.enabled new expected value in Safest security level

From https://tails.boum.org/blueprint/monthly_report/report_2020_09/#index5h1: a lot of people reached the helpdesk complaining about JavaScript not being disabled by Tor Browser's safest mode anymore: NoScript is doing that job now, as intended.

More specifically, in the Safest security mode, the javascript.enabled pref is enabled, which is why users are confused. NoScript blocks JavaScript anyway.

Please document this in https://tails.boum.org/news/version_4.11/ known issues :)

Thanks!