[Docs] Descriptions for rank eval and mterm parameters

[Naarcha-AWS]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[github-actions]

Changes Analysis

Commit SHA: 9c177fd
Comparing To SHA: 4c48c26

API Changes

Summary

└─┬Components
  ├─┬_core.rank_eval:RankEvalMetricDiscountedCumulativeGain
  │ ├─┬ALLOF
  │ │ └──[🔀] $ref (41722:13)❌ 
  │ └─┬ALLOF
  │   └──[🔀] $ref (41758:11)❌ 
  ├─┬_core.rank_eval:RankEvalMetricBase
  │ └─┬k
  │   └──[🔀] description (41725:24)
  ├─┬_core.rank_eval:RankEvalRequestItem
  │ └─┬ratings
  │   └──[🔀] description (41814:24)
  ├─┬_core.mtermvectors:Operation
  │ ├─┬payloads
  │ │ └──[🔀] description (41631:24)
  │ ├─┬positions
  │ │ └──[🔀] description (41634:24)
  │ ├─┬doc
  │ │ └──[🔀] description (41618:24)
  │ ├─┬field_statistics
  │ │ └──[🔀] description (41623:24)
  │ └─┬offsets
  │   └──[🔀] description (41628:24)
  ├─┬_core.rank_eval:RankEvalMetricPrecision
  │ └─┬ALLOF
  │   └─┬ignore_unlabeled
  │     └──[🔀] description (41783:28)
  ├─┬_core.rank_eval:RankEvalMetricRatingThreshold
  │ ├─┬ALLOF
  │ │ └──[🔀] $ref (41788:11)❌ 
  │ └─┬ALLOF
  │   └──[🔀] $ref (41722:13)❌ 
  ├─┬_core.rank_eval:DocumentRating
  │ └─┬rating
  │   └──[🔀] description (41677:24)
  └─┬_core.rank_eval:RankEvalMetricDetail
    ├─┬hits
    │ └──[🔀] description (41739:24)
    ├─┬unrated_docs
    │ └──[🔀] description (41734:24)
    ├─┬metric_score
    │ └──[🔀] description (41731:24)
    └─┬metric_details
      └──[🔀] description (41744:24)

Document Element	Total Changes	Breaking Changes
components	17	8

• ❌ BREAKING Changes: 8 out of 17
• Modifications: 17
• Breaking Modifications: 4

Report

The full API changes report is available at: https://github.com/opensearch-project/opensearch-api-specification/actions/runs/11391726267/artifacts/2070826269

API Coverage

	Before	After	Δ
Covered (%)	588 (57.59 %)	588 (57.59 %)	0 (0 %)
Uncovered (%)	433 (42.41 %)	433 (42.41 %)	0 (0 %)
Unknown	29	29	0

[github-actions]

Spec Test Coverage Analysis

Total	Tested
504	317 (62.9 %)

[natebower]

@Naarcha-AWS Can we reopen this for editorial review? Thanks!

[dblock]

@natebower Sorry, this got merged without it. Let's think about a workflow where we can wait for editorial reviews for content if this is something we can do continuously moving forward?

[natebower]

@dblock No worries. That is our current workflow 😄. @Naarcha-AWS will coordinate review(s) and notify when ready to merge. Thanks!

[dblock]

@Naarcha-AWS @natebower Probably easiest is to keep these in draft until they can be merged?