docs: we don't use this as a parent pom (#407)

@BenWhitehead

Author: elharo

README.md

@@ -7,7 +7,7 @@ Shared Maven dependencies for Google Cloud Java client libraries.
 ## Quickstart
 
 [//]: # ({x-version-update-start:google-cloud-shared-dependencies:released})
-If you are using Maven, use this artifact as your project's parent.
+If you are using Maven, add this to the `dependencyManagement` section.
 ```xml
 <dependencyManagement>
   <dependencies>
@@ -48,4 +48,4 @@ Apache 2.0 - See [LICENSE][license] for more information.
 [maven-version-link]: https://search.maven.org/search?q=g:com.google.cloud%20AND%20a:google-cloud-shared-dependencies&core=gav
 [contributing]: https://github.com/googleapis/java-shared-dependencies/blob/master/CONTRIBUTING.md
 [code-of-conduct]: https://github.com/googleapis/java-shared-dependencies/blob/master/CODE_OF_CONDUCT.md#contributor-code-of-conduct
-[license]: https://github.com/googleapis/java-shared-dependencies/blob/master/LICENSE
+[license]: https://github.com/googleapis/java-shared-dependencies/blob/master/LICENSE