Add OpenSearch operator example to data-store.md

[randerzander]

Added snippet about how to use a custom vdb operator to docs page

Description

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• If adjusting docker-compose.yaml environment variables have you ensured those are mimicked in the Helm values.yaml file.

[nkmcalli]

Suggested change

	Once you have built a data store or will use one provided by a 3rd party, you can create the operator and feed it as input to the vdb_upload function. For example:
	After you have built a data store, or if you intend to use one provided by a 3rd party, you can create the operator. Provide the operator as input to the vdb_upload function. For example, use the following code:

[nkmcalli]

@randerzander , Is this PR still needed? Minor suggestion here.