Update Dataproc Documentation. (#1708)

This PR was generated using Autosynth. 🌈

Here's the log from Synthtool:
```
synthtool > Executing /tmpfs/src/git/autosynth/working_repo/Dataproc/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:f3d61ae45abaeefb6be5f228cda22732c2f1b00fb687c79c4bd4f2c42bb1e1a7
Status: Image is up to date for googleapis/artman:latest
synthtool > Cloning googleapis.
synthtool > Running generator for google/cloud/dataproc/artman_dataproc_v1.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/php/google-cloud-dataproc-v1.
synthtool > Replaced 'ListJobsRequest_JobStateMatcher' in src/V1/Gapic/JobControllerGapicClient.php.
synthtool > Running generator for google/cloud/dataproc/artman_dataproc_v1beta2.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/php/google-cloud-dataproc-v1beta2.
synthtool > Replaced 'ListJobsRequest_JobStateMatcher' in src/V1beta2/Gapic/JobControllerGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/Gapic/ClusterControllerGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/ClusterControllerClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/Gapic/JobControllerGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/JobControllerClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/Gapic/JobControllerGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/Gapic/WorkflowTemplateServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/Gapic/ClusterControllerGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/ClusterControllerClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/ClusterControllerGrpcClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/WorkflowTemplateServiceGrpcClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/JobControllerGrpcClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/WorkflowTemplateServiceClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1beta2/JobControllerClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/Gapic/WorkflowTemplateServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V1/WorkflowTemplateServiceClient.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/System/V1/ClusterControllerSmokeTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1/JobControllerClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1/WorkflowTemplateServiceClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1/ClusterControllerClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/System/V1beta2/ClusterControllerSmokeTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1beta2/JobControllerClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1beta2/WorkflowTemplateServiceClientTest.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V1beta2/ClusterControllerClientTest.php.
synthtool > Cleaned up 1 temporary directories.
synthtool > Wrote metadata to synth.metadata.

```