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

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

plugins/pbcopy/README.md

-# pbcopy
-> OSX's pbcopy and pbpaste for Linux
-
-pbcopy paste data from the clipboard to STDOUT.
-pbpaste paste data from the clipboard.
-
-## Usage
-
-Copy a list of files in your home directory to the OS X clipboard:
-```fish
-$ ls ~ | pbcopy
-```
-
-Copy the contents of a file to the clipboard:
-```fish
-$ pbcopy < cookies.txt
-```
-
-Copy part of a file to the clipboard
-```fish
-$ grep 'ip address' serverlist.txt | pbcopy
-```
-
-Paste from your clipboard to stdout
-echo `pbpaste`
-```fish
-$ pbpaste
-```
-
-Paste from your clipboard to a file
-```fish
-$ pbpaste > clipboard.txt
-```
-
-Paste from your clipboard to a file in a remote host
-```fish
-$ pbpaste | ssh username@host 'cat > ~/myclipboard.txt'
-```
\ No newline at end of file

plugins/pbcopy/pbcopy.fish

-function pbcopy --description "Copy data from STDIN to the clipboard"
-  xsel --clipboard --input
-end
-
-function pbpaste  --description "Paste data from the Clipboard"
-  xsel --clipboard --output
-end