split up "normal completion" and "fuzzy completion integration"

[laalsaas]

• [x] I have read through the manual page (man fzf)
• [x] I have the latest version of fzf
• [x] I have searched through the existing issues

Info

• OS
  • [x] Linux (NixOS)
  • [ ] Mac OS X
  • [ ] Windows
  • [ ] Etc.
• Shell
  • [x] bash
  • [ ] zsh
  • [ ] fish

Problem / Steps to reproduce

I think it would be good to split up the completion.bash file, and differentiate between the regular tab completion of options to fzf, which can be installed inside the normal bash completion directory like any completion script on the one hand, and the fuzzy completions of every other command, using fzf to display the possibilities on the other hand.

This enables users to opt for not using the fzf fuzzy completion for commands, but they can still get proper completion of fzf options. It also makes the packaging process easier, or at least more standardized.

I think the same thing also goes for zsh, but i haven't checked.

[junegunn]

The completion for fzf itself is only provided for bash and it hasn't been maintained for quite a while. I may decide to remove it in the future.