fzf: make sort by relevance the default

In the FZF README, under the section for command line history, it states:

CTRL-R – Paste the selected command from history onto the command-line

  • If you want to see the commands in chronological order, press CTRL-R again which toggles sorting by relevance

I find that I almost always get the best results when toggling that.

How can I configure it to be on by default for CTRL-R?