app-shells/fzf: bump to 0.21.1

app-shells/fzf: bump to 0.21.1

Highlights:
* Install fzf(1) manual page
* Replace einfo with elog; einfo is muted when emerge is running
  in parallel mode
* Make shell commands easier to spot in elog messages
* Clarify that bash keybindings are in fact keybindings and are in fact
  bash-specific
* Remove kinda pointless optfeature noise

Closes: https://bugs.gentoo.org/719346
Signed-off-by: Olaf Torvaldsson <consus@ftml.net>
Closes: https://github.com/gentoo/gentoo/pull/15511
Signed-off-by: Joonas Niilola <juippis@gentoo.org>