docs: Change link to REUSE Specification

Author: sorairolake

CONTRIBUTING.adoc

@@ -29,7 +29,7 @@ Please see the {commit-messages-guide-url}[Commit messages guide] and the
   case if possible. Note that the change must pass the CI.
 . Please update the copyright information if possible. This project is
   compliant with version 3.3 of the
-  https://reuse.software/spec/[_REUSE Specification_].
+  https://reuse.software/spec-3.3/[_REUSE Specification_].
   https://github.com/fsfe/reuse-tool[`reuse`] is useful for updating the
   copyright information.
 . Please update the link:CHANGELOG.adoc[Changelog] if possible.

README.md

@@ -132,4 +132,4 @@ licensing information.
 [CHANGELOG.adoc]: CHANGELOG.adoc
 [CONTRIBUTING.adoc]: CONTRIBUTING.adoc
 [AUTHORS.adoc]: AUTHORS.adoc
-[_REUSE Specification_]: https://reuse.software/spec/
+[_REUSE Specification_]: https://reuse.software/spec-3.3/