README update

Author: namedgraph

README.md

@@ -1,3 +1,9 @@
 # RDF syntax check
 GH action that iterates all RDF files in the repository and validates their syntax using [Apache Jena's riot parser](https://jena.apache.org/documentation/io/#command-line-tools).
-The action fails as soon as an invalid file is detected.
+The action fails as soon as an invalid file is detected.
+
+## Usage
+
+```yml
+- uses: AtomGraph/[email protected]
+```