Merge pull request opencontainers#677 from AkihiroSuda/fix-typo

annotations: fix a hyperlink

Author: stevvooe

annotations.md

@@ -25,5 +25,5 @@ This specification defines the following annotation keys, intended for but not l
 * **org.opencontainers.image.version** [Semantic versioning-compatible](http://semver.org/) version of the packaged software.
 * **org.opencontainers.image.revision** Source control revision identifier for packaged software.
 * **org.opencontainers.image.vendor** Name of the distributing entity, organization or individual.
-* **org.opencontainers.image.licenses** Comma-separated list of licenses under which contained software is distributed, in [SPDX Short identifier]https://spdx.org/licenses/] form.
+* **org.opencontainers.image.licenses** Comma-separated list of licenses under which contained software is distributed, in [SPDX Short identifier](https://spdx.org/licenses/) form.
 * **org.opencontainers.image.ref.name** Name of the reference for a target (string). SHOULD only be considered valid when on descriptors on `index.json` within [image layout](image-layout.md).