turns out that the README.md explains that "... licensed under MIT ...
the LICENSE does not have to be bundled as long as ..." but the scripts
themselfs don't mention any license.
fixed that by adding a one line mention of the used license and the two
lines explaining that the header comments have to stay intact.
* Make the license less restrictive. See #14
So that people can use _just_ main.sh without bothering with also
distributing the license
* Add license update to changelog
* Add a comment about expansion, see #26
* Use an unmodified MIT License, with the more permissive clause inside the code
As modifying the MIT License will needlessly (but rightfully) cause
suspicion
* Credit @bravo-kernel for his feedback
* Fix another typo
* Reword copyright
