Merge pull request #106 from zazuko/readme-shapes

docs: dereferencing shapes

README.md

@@ -6,6 +6,17 @@ In this repository we develop the *Cube Schema* model.
 
 DRAFT: https://zazuko.github.io/cube-link/
 
+## Validation shapes
+
+The [validation](validation) directory contains various SHACL Shapes which can be used to ensure the correctness of datasets, cubes, hierarchies, and other.
+
+They can be retrieved from the web using an URI in the form of `https://cube.link/{VERSION}/shape/{CONSTRAINT}`, where the `{CONSTRAINT}` variable is replaced with any of the shape documents (without `.ttl`) and the `{VERSION}` variable is replaced with any [tag name](https://github.com/zazuko/cube-link/tags) or the word `latest`.
+It is recommended to always use a specific version to avoid breaking changes.
+
+For example, to get version 0.0.4 of `standalone-cube-constraint.ttl`, fetch https://cube.link/v0.0.4/shape/standalone-cube-constraint .
+
+Otherwise, to get the latest version, fetch https://cube.link/latest/shape/standalone-cube-constraint instead.
+
 ## How to Contribute
 
 Please open [Issues](https://github.com/zazuko/cube-link/issues) on this repository or provide PRs for contributions.