Contribution: Shell autocompletion files for fpm

[braph]

Hello!

I'm a very happy user of fpm and I would like to contribute to the project by providing shell autocompletion files. I have created completion files for all major shells (Bash, Fish, and Zsh) using my crazy-complete tool.

You can access the definition file for the fpm completions here and the actual generated autocompletion files can be found here.

I initially created the structure of the definition file by parsing the help text from fpm, and then I manually enhanced the options to include the complete attribute.

Thank you for your great work on fpm!

Best regards,

Benjamin Abendroth