* refactor: allow version matrixes by projects
* feat: add initial version-matrix for mage-os
* feat: add project as optional input to action
* docs: document new input
* refactor: tighten types a bit
* chore: apply change requests from code review
Previously, @danslo reported that he tried to use `custom_versions` without
setting the kind. This isn't the correct behavior.
I've added a validator to alert him of this.
`kind` is a new input property for the `supported-version` action which
allows one to define what specific versions of Magento they support.
Currently, `kind` supports `latest`, `currently-supported`, and `custom`. See the
README for `supported-version` if you want more specifics
Damien Retzinger
Vinai Kopp