[DOC] Add documentation for Flow Framework Reprovision parameter

[dbwiddis]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request.

A reprovision parameter was added to Flow Framework update template (PUT) API:

• Adds reprovision API to support updating search pipelines, ingest pipelines index settings flow-framework#804

Version: List the OpenSearch version to which this issue applies, e.g. 2.14, 2.12--2.14, or all.

New in 2.17.0

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

Linked PR has pretty through description of the feature.

Sorry this was missed; I'll get a PR up soon.