Add metadata fields for mappings (content gap initiative)

[vagimeli]

Description

Add documentation to address content gaps

Issues Resolved

Closes #4300
See also PR #7115

Checklist

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[vagimeli]

Status = Need SME for tech review and to answer the following questions:

1. What are the mapping limits settings, their default values, and how to configure them if needed.
2. Does OpenSearch allow removal of mapping types and defining mapping types within an index? If so, SME should provide information to include in documentation. Do we have guidance on how to structure data without relying on mapping types?
3. How does user delete a mapping? Provide example tutorial.

[mgodwan]

Does OpenSearch allow removal of mapping types and defining mapping types within an index?

Do you mean custom types here which were present in earlier versions on elasticsearch? If yes, the mapping types have been deprecated since OS 1.0 itself

[vagimeli]

Does OpenSearch allow removal of mapping types and defining mapping types within an index?

Do you mean custom types here which were present in earlier versions on elasticsearch? If yes, the mapping types have been deprecated since OS 1.0 itself

We can note this in the documentation. We do need to include information and examples about deleting a mapping. Will you help with that topic too?

[vagimeli]

@mgodwan I've added first-pass drafts of the mappings documentation. When you review these docs, please verify that the code examples are relevant (I tested them using Dev Tools, but am not sure if these examples are most relevant to our users.) Also, please verify that the narrative text is accurate and I haven't miscommunicated any information. Thank you!