Introducing `show` as a new subcommand of `forgit`, an interactive
version of `git show`. The configured default alias is `gso`.
Alt-T can be used to toggle between showing the diff and the commit
message in the fzf preview window.
The new command in used instead of `forgit diff` when pressing enter
in `forgit log`. This fixes the display of diffs for merge commits.
**Note**: we have a requirement for the `fzf` version now. The minimum
required `fzf` version is 0.49.0. If the installed version is lower,
forgit will exit with an error message.
Fixes#416.
fish's builtin git completion automatically registers git-forgit completions as completions for forgit subcommand of git. Therefore this PR provides completions for both formats git-forgit and git forgit.
Simple subcommands get the completion list from __fish_git_* functions, while others requiring more than 1 __fish_git_* completion sources reuse the completion items from the corresponding git commands.
