[split] Move gi plugin to oh-my-fish/plugin-gi

https://github.com/oh-my-fish/plugin-gi

plugins/gi/README.md

-gitignore (gi) plugin
-=====================
-
-This plugin provides a simple command line interface to gitignore.io - a
-website that generates .gitignore files based on your project requirements.
-
-## Completions
-
-The first step is to download the latest language list from gitignore.io so
-that the fish completions can be updated.  Run `gi update-completions` to
-download the completions, they will be stored in
-`~/.config/fish/completions/gi.fish`
-
-You should repeat this occasionally to keep up to date.
-
-## Usage
-
-Type `gi` followed by TAB to view the list of languages available.  To generate
-a .gitignore file, specify the list of languages you are interested in and pipe
-the output into the destination file.  Example for a go-lang project:
-
-    gi go tags vagrant > .gitignore
-    git add .gitignore

plugins/gi/_update_gi_completions.fish

-function _update_gi_completions -d "Update completions for gitignore.io"
-  set compl_dir ~/.config/fish/completions
-  set compl_file "$compl_dir/gi.fish"
-
-  # Download list of ignore types
-  set -l gi_list (gi list | tr ',' ' ')
-  if test -z $gi_list
-    echo "No result returned from gitignore.io" >&2
-    return 1
-  end
-
-  # Backup existing completions
-  if test -e $compl_file
-    mv -f $compl_file {$compl_file}.bak
-  else if not test -d $compl_dir
-    mkdir -p $compl_dir
-  end
-
-  # Output new completions
-  echo complete -c gi -a \"update-completions $gi_list\" >$compl_file
-end

plugins/gi/gi.fish

-function gi -d "gitignore.io cli for fish"
-  if test $argv[1] = 'update-completions'
-    _update_gi_completions
-    return $status
-  end
-
-  set -l params (echo $argv|tr ' ' ',')
-  curl -s https://www.gitignore.io/api/$params
-end