Docs: Missing `datastore_v1` documentation.

[lrnq]

As noted in this comment the documentation for datastore_v1 is missing from the documentation. It would be appreciated if the docs were updated.

[daniel-sanche]

To add context: It looks like the docs/ folder only includes veneer classes, not any of the auto-generated classes from datastore_v1. To get the auto-generated files to show up, we'll likely need to change something in the owlbot file. And we'll need to update index.rst to point to the auto-generated docs folder

See python-aiplatform/docs for a way to organize this

[shubham-arora-18]

+1 On the issue. Its hard to understand how to: Put, get and query via DatastoreAsyncClient.