Bash Completion Wrapper

- [ 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
- [ ] Mac OS X
- [ ] Windows
- [ ] Etc.
- Shell
- [ x] bash
- [ ] zsh
- [ ] fish

## Problem / Steps to reproduce

I have lots of git aliases which i find sometimes hard to remember . I do have git bash autocompletion , but i'd like to integrate it with fzf .

Checked : https://github.com/junegunn/fzf#custom-fuzzy-completion

And wrote something similar :

But it doesnt seem to work .
Any pointers ?

Thanks

Start with fzf's documented custom fuzzy completion and compare it with the reported Git Bash completion setup and wrapper shown in the issue. Reproduce the behavior on Linux with Bash and determine what integration is missing; done means Git aliases complete through fzf as intended.

Written by the indexing model from the issue text.