Please support Firefox [Dark] Themes #24
Description
Even though #20 seems to indicate that HistoryInThreads did support/apply Firefox [Dark] Themes, it doesn't apply/use Firefox's standard "Dark" theme.
For other extensions this varies theme by theme. "System theme - auto" theme doesn't apply my GNOME dark theme to https://github.com/aaFn/Bookmark-search-plus-2, but "Dark" theme does work with https://github.com/aaFn/Bookmark-search-plus-2.
(Firefox 96.0.2)