- Key hint footer had no off switch. $FZF_DEFAULT_OPTS could not give one,
since fzf reads it before the options fzf.vim passes
- Merged ahead of the per-call and command-level options, so both still
take precedence
- '--no-footer' there hides the hints. Documented as fzf-vim-key-hints,
the footer had no name to look up
- Help TOC also gained Paste key and Show key, missing since those
sections were added
Close#1623