[FEATURE] Support additional parameters for semantic_search (other?) workflows

[Jon-AtAWS]

Is your feature request related to a problem?

When running the semantic_search workflow, I may have additional settings for the index.

• Shards, replicas, and other index settings
• Specific mappings for metadata fields

Currently I can't add replica settings (?), I just get whatever the default is. I can update the mapping before I use the index, but it would be better if I could pass them in to the workflow.

What solution would you like?

1. document all possible parameters for each of the templates. (roleArn is not in the template and I don't see it in the documentation. If number_of_replicas is allowed, I don't see it.
2. Add these parameters.
   "create_index.settings.number_of_replicas": "1",
   "create_index.settings.mappings": { dict, with the contents of the "mappings" key for the create_index API }

I see there are create_index.settings.mappings parameters for the model parameters and hyper parameters. Maybe just collapse everything into a single create_index.settings that takes the whole create index body? You can still support a pipeline_name parameter

This request applies to many of the templates where you need to define attributes or index parameters. Maybe there's a more generic solution?

[andrross]

Catch All Triage - 1 2 3 4

@dbwiddis Can a maintainer take a look at this request? Thanks!