Debian packages bat (ls replacement) as `batcat`, while other distros,
like archlinux, does not. This commits selects which binary to use
depending if the current distro is debian.
Also, debian's package for fzf places the zsh completitions file in
other directory of what arch linux does, this commit also fixes this.
Changes:
- Refactored into a function, instead of alias
- Renamed to fzf_fast_file_edit, in place of ce, which is more
descriptive
- Made the code easier to read and edit
