Release Version 1.0.0

This is the first standalone release of `magic.bash`, a library with *Useful functions I don't want
to write twice*.

The library was previously used (in a very similar form) by many other of my shell scripts, and
until now it has been living [in my `shell-helpers` repository][1]. Since I've come to use it across
multiple other projects, though, I decided it is time to publish this in a way that gives it more
visibility and better maintenance.

Since the API has been stable for ~2 years now I'm skipping major version 0 in favor of an immediate
stable release.

Happy scripting!

[1]: https://gitlab.com/c8160/shell-helpers