Add documentation for new bloom filter settings

_install-and-configure/configuring-opensearch/index-settings.md

@@ -182,6 +182,10 @@ OpenSearch supports the following dynamic index-level index settings:
 
 - `index.final_pipeline` (String): The final ingest node pipeline for the index. If the final pipeline is set and the pipeline does not exist, then index requests fail. The pipeline name `_none` specifies that the index does not have an ingest pipeline.
 
+- `index.optimize_doc_id_lookup.fuzzy_set.enabled` (Boolean): This setting controls whether `fuzzy_set` should be enabled in order to optimize document ID lookups in index or search calls by using an additional data structure, in this case, the Bloom filter data structure. Enabling this setting improves performance for upsert and search operations that rely on document ID by creating a new data structure (Bloom filter). The Bloom filter allows for the handling of negative cases (that is, IDs being absent in the existing index) through faster off-heap lookups. Default is `false`. This setting can only be used if the feature flag `opensearch.experimental.optimize_doc_id_lookup.fuzzy_set.enabled` is set to `true`.
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+- `index.optimize_doc_id_lookup.fuzzy_set.false_positive_probability` (Double): Sets the false-positive probability for the underlying `fuzzy_set` (that is, the Bloom filter). A lower false-positive probability ensures higher throughput for `UPSERT` and `GET` operations. Allowed values range between `0.01` and `0.50`. Default is `0.20`. This setting can only be used if the feature flag `opensearch.experimental.optimize_doc_id_lookup.fuzzy_set.enabled` is set to `true`.
+
 ### Updating a dynamic index setting
 
 You can update a dynamic index setting at any time through the API. For example, to update the refresh interval, use the following request: