add ai sandbox docs (#978)

Signed-off-by: Mark Nelson <mark.x.nelson@oracle.com>

Author: markxnelson

docs-source/spring/content/_index.md

@@ -12,6 +12,23 @@ Oracle Backend for Microservices and AI allows developers to build microservices
 
 If you are building Spring Boot applications with Oracle Database, you should also check out [Spring Cloud Oracle](https://github.com/oracle/spring-cloud-oracle) which is the home of a number of the components used in Oracle Backend for Microservices and AI, and which you can also use in your own applications!
 
+## New Developer Preview Feature - Oracle AI Microservices Sandbox
+
+Oracle Backend for Microservices and AI Version 1.3.1 introduces [Oracle AI Microservices Sandbox](https://github.com/oracle-samples/oaim-sandbox) as a *Developer Preview* feature.  
+
+The Oracle AI Microservices Sandbox provides a streamlined environment where developers and data scientists can explore the potential of Generative Artificial Intelligence (GenAI) combined with Retrieval-Augmented Generation (RAG) capabilities. By integrating Oracle Database 23ai AI Vector Search, the Sandbox enables users to enhance existing Large Language Models (LLMs) through RAG.
+
+It provides a "sandbox" for experimentation and iteration, allowing you to easily optimize a chatbot/RAG use case by exploring different models, chunking strategies, vector similarity algorithms, prompts, model parameters, memory, re-ranking, and evaluation.  
+
+![AI Microservices Sandbox](./ai-microservices-sandbox.png)
+
+This feature is provided as a "developer preview" meaning it is provided for developers to experiment with, without any formal support, but with the expectation that it may become a formal feature in a future release.  You may open issues in GitHub and best-effort assistance will be provided.  Please be aware that this feature is under development, and not yet considered stable.  Functionality, interfaces, etc., may change in non-backwards compatible ways.  
+
+For more information about this developer preview feature, please visit:
+ - the [GitHub repo](https://github.com/oracle-samples/oaim-sandbox) 
+ - the [documentation](https://oracle-samples.github.io/oaim-sandbox/)
+ - this OCI Cloud Coaching session titled [Building a real chatbot with Oracle Database 23ai](https://www.youtube.com/watch?v=oG9MPCpwUlU), (video) which includes discussion of the background concepts and a demonstration of this feature
+
 ## Try it out with CloudBank AI
 
 To learn more about deploying and using Oracle Backend for Microservices and AI, we recommend our

docs-source/spring/content/release-notes/_index.md

@@ -4,9 +4,16 @@ description: "Release notes for Oracle Backend for Microservices and AI includin
 keywords: "release notes additions updates deprecations removals springboot spring development microservices development oracle backend"
 ---
 
+## Version 1.3.1, October 23rd, 2024
+
+This release includes the following changes:
+
+- Added Oracle Autonomous Database 23ai as the default option for the database on OCI deployments, 19c still available as an option
+- Added the Oracle AI Microservices Sandbox as a developer preview feature
+
 ## Version 1.3.0, September 5th, 2024
 
-This release include:
+This release includes:
 
 - IntelliJ Plugin
 - Optional GPU node pool