docs(webrisk): update docs configuration (via synth)

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Log from Synthtool

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/webrisk/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:c773192618c608a7a0415dd95282f841f8e6bcdef7dd760a988c93b77a64bd57
Status: Image is up to date for googleapis/artman:latest
synthtool > Cloning googleapis.
synthtool > Running generator for google/cloud/webrisk/artman_webrisk_v1beta1.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/webrisk-v1beta1.
synthtool > Copy: /home/kbuilder/.cache/synthtool/googleapis/google/cloud/webrisk/v1beta1/webrisk.proto to /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/webrisk-v1beta1/google/cloud/webrisk_v1beta1/proto/webrisk.proto
synthtool > Placed proto files into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/python/webrisk-v1beta1/google/cloud/webrisk_v1beta1/proto.
synthtool > Replaced '__doc__ = """Attributes:' in google/cloud/webrisk_v1beta1/proto/webrisk_pb2.py.
.coveragerc
.flake8
MANIFEST.in
docs/_static/custom.css
docs/_templates/layout.html
noxfile.py.j2
setup.cfg
Running session blacken
Creating virtual environment (virtualenv) using python3.6 in .nox/blacken
pip install black
black google tests docs
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/__init__.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/__init__.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/__init__.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/gapic/enums.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/gapic/web_risk_service_v1_beta1_client_config.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/gapic/transports/web_risk_service_v1_beta1_grpc_transport.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/docs/conf.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/types.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/proto/webrisk_pb2_grpc.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/gapic/web_risk_service_v1_beta1_client.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/tests/unit/gapic/v1beta1/test_web_risk_service_v1_beta1_client_v1beta1.py
reformatted /tmpfs/src/git/autosynth/working_repo/webrisk/google/cloud/webrisk_v1beta1/proto/webrisk_pb2.py
All done! ✨ 🍰 ✨
13 files reformatted, 3 files left unchanged.
Session blacken was successful.
synthtool > Cleaned up 2 temporary directories.
synthtool > Wrote metadata to synth.metadata.