Add 3.1 to version history (#10138)

Signed-off-by: Fanit Kolchina <kolchfa@amazon.com>

Author: kolchfa-aws

_about/version-history.md

@@ -9,6 +9,7 @@ permalink: /version-history/
 
 OpenSearch version | Release highlights | Release date  
 :--- | :--- | :--- 
+[3.1.0](https://github.com/opensearch-project/opensearch-build/blob/main/release-notes/opensearch-release-notes-3.1.0.md) | Makes GPU acceleration for vector index builds generally available. Introduces memory-optimized search for Faiss indexes using Lucene HNSW, semantic field type for streamlined semantic search, and Search Relevance Workbench for search quality optimization. Makes star-tree indexes generally available with support for comprehensive query types. Enhances observability with ML Commons metrics integration, custom index support for OpenTelemetry data, and new PPL commands for JSON manipulation. Improves agent management with Update Agent API and persistent MCP tools. Includes security enhancements with immutable user objects and new resource sharing framework. For a full list of release highlights, see the Release Notes. | 24 June 2025
 [3.0.0](https://github.com/opensearch-project/opensearch-build/blob/main/release-notes/opensearch-release-notes-3.0.0.md) | Upgrades to Lucene 10 for improved indexing and vector search. Adds experimental gRPC support and pull-based ingestion from Kafka and Kinesis. Introduces GPU acceleration for vector operations and semantic sentence highlighting. Improves range query performance and hybrid search with z-score normalization. Adds plan-execute-reflect agents and native MCP protocol support for agentic workflows. Enhances security with a new Java agent replacing the Security Manager. Includes PPL query improvements with lookup, join, and subsearch commands. For a full list of release highlights, see the Release Notes. | 06 May 2025
 [2.19.2](https://github.com/opensearch-project/opensearch-build/blob/main/release-notes/opensearch-release-notes-2.19.2.md) |  Improves query insights with better index handling, a new verbose API parameter, and a default index template. Fixes bugs across Query Insights, Observability, Flow Framework, and Dashboards. Includes multiple CVE fixes, test enhancements, and a new PGP key for artifact verification. For a full list of release highlights, see the Release Notes. | 29 April 2025
 [2.19.1](https://github.com/opensearch-project/opensearch-build/blob/main/release-notes/opensearch-release-notes-2.19.1.md) |  Adds execution hint for cardinality aggregator. Includes bug fixes for ML Commons, Query Insights Dashboards, and Remote Metadata SDK. Contains maintenance updates for several components. For a full list of release highlights, see the Release Notes. | 27 February 2025