license: Supports REUSE compatible projects

[sorairolake]

According to current automatic merging guidelines, the license file must be located in the project root directory:

License: The package should have an OSI-approved software license located in the top-level directory of the package code, e.g. in a file named LICENSE or LICENSE.md. This check is required for the General registry. For other registries, registry maintainers have the option to disable this check.

On the other hand, the REUSE Specification¹ requires that the license file must be placed in the LICENSES/ directory located in the project root directory. Therefore, they are incompatible.

I faced this issue before and solved it then by creating the license file as a symbolic link (e.g., LICENSE.MIT to LICENSES/MIT.txt) which followed the guidelines. However, I don't think this is a good solution, so I think it would be better to support compatibility with the REUSE Specification.

Footnotes

1. REUSE was started by the Free Software Foundation Europe (FSFE) to provide a set of recommendations to make licensing your Free Software projects easy, comprehensive, unambiguous, and machine-readable. ↩

[ericphanson]

I would be okay with also searching LICENSES, it seems obvious enough that the license isn’t hidden or hard to find