Add workaround for Checkstyle error, closes #6216 (#6593)

* Add workaround for Checkstyle error, closes #6216

Signed-off-by: Martijn Verburg <martijnverburg@gmail.com>

* Update CONTRIBUTING.md

Updates to workaround section.

* Update CONTRIBUTING.md

Minor fix to use correct reference

Co-authored-by: Alan Zimmer <48699787+alzimmermsft@users.noreply.github.com>

CONTRIBUTING.md

@@ -87,6 +87,22 @@ Some live tests may have additional steps for setting up live testing resources.
 See the CONTRIBUTING.md file for the service you wish to test for additional
 information or instructions.
 
+### Workaround for Checkstyle error
+
+When building locally you might run into a Checkstyle such as the following:
+
+```
+Execution default of goal org.apache.maven.plugins:maven-checkstyle-plugin:3.1.0:check failed:
+Plugin org.apache.maven.plugins:maven-checkstyle-plugin:3.1.0 or one of its dependencies could not be resolved: 
+Could not find artifact com.azure:sdk-build-tools:jar:1.0.0 in ossrh (https://oss.sonatype.org/content/repositories/snapshots/)
+```
+
+This is because the `sdk-build-tools` project isn't released to Maven. To resolve this issue you'll need to copy the `eng` folder locally then install `sdk-build-tools`.
+
+`mvn clean install eng/code-quality-reports/pom.xml`
+
+All code in the Azure SDKs for Java repository must pass Checkstyle before being merged. The `sdk-build-tools` is updated periodically, so if a new branch fails Checkstyle you'll need to reinstall.
+
 ## Versions and versioning
 
 Tooling has been introduced to centralize versioning and help ease the pain of updating artifact versions in POM and README files. Under the eng\versioning directory there exists version text files, one for client ([version_client.txt](./eng/versioning/version_client.txt)) and one for data ([version_data.txt](./eng/versioning/version_data.txt)). The format of the version files is as follows: