added a transfer.sh plugin (#5854)

* added a transfer.sh plugin
created a function to easily upload files to transfer.sh file sharing site
Usage : transfer file.txt

* added README for transfer.sh plugin

* replaced transfer function with @nl5887 version

* updated transfer README.md

* modified the script to use tar command instead of zip

* Update README formatting

Co-authored-by: Remco Verhoef <remco@dutchcoders.io>