reuse-tool should allow README files in the LICENSES directory

[brlin-tw]

It is a common practice to add README files in directories for documentation purposes. Currently, doing so in the LICENSES directory will trigger the following error:

reuse.project - WARNING - Could not resolve SPDX License Identifier of LICENSES/README.md, resolving to README. Make sure the license is in the license list found at <https://spdx.org/licenses/> or that it starts with 'LicenseRef-', and that it has a file extension.
# BAD LICENSES

'README' found in:
* LICENSES/README.md

# SUMMARY

* Bad licenses: README

IMO directory README files should be treated as a special case and be ignored by reuse-tool.

[brlin-tw]

Hello, I like to work on this so can you assign it to me.

I'm appreciated but I don't have the permission to assign this issue to anyone, feel free to do it.

[mxmehl]

Sounds reasonable, but we should only allow for very specific files. The specification does not mention that no other files except the actual licenses are allowed in LICENSES/, but I would like to make the list of allowed other files explicit.

What about README with the file extensions md, txt and rst? Or shall we even rule out txt to never conflict with the license files?

This could only backfire if there was a SPDX license called README, which hopefully will never occur.

[brlin-tw]

What about README with the file extensions md, txt and rst? Or shall we even rule out txt to never conflict with the license files?

I'd say any filename starting with README. should be allowed so that documentation can be excluded regardless of the format. If any licenses have to be named README they should be special-cased instead.

[silverhook]

What is the intended use of the LICENSES/README* that is different from the README* file in the root directory?

Regarding documentation, so far the position was still that it has to carry a license (any copyright statement), but can be done in a *.licenses file (or globbed in the future in .reuse). So far I fail to see a compelling reason to add exceptions for that, least we snowball into “exclude this, exclude that”.

[mxmehl]

I am very torn. I see the benefit of showing a nice explanation when someone clicks on the LICENSES folder. On the other hand, it adds more exceptions and complexity, spec- and tool-wise.

@brlin-tw Would you agree to these concerns?

[floriansnow]

I see no reason to have a README with the licenses themselves because I think any information that might go in there could easily go in a section about licenses in the main README file. I am happy to be convinced otherwise, though.