docs build failed in `google-shopping-merchant-accounts`

[ohmayr]

See https://github.com/googleapis/google-cloud-python/actions/runs/9390578475/job/25860763929?pr=12769#step:5:863

The docs build failed because of the following reasons:

• asterisk characters were not surrounded by backticks or escaped.
• unexpected section title
• unexpected indent

See the fix: https://github.com/googleapis/google-cloud-python/pull/12769/commits/feccc8bec2cd65f4573bf36cf09a5d248360ce51