DA-1319: Update haystack demo per 8.0 (#73)

* DA-1319: update: frontmatter and tutorial content for RAG with Couchbase and OpenAI

- Changed tutorial path and titles to reflect the use of Couchbase Search Vector Index instead of FTS.
- Updated descriptions to clarify the integration of Couchbase's vector search capabilities with OpenAI embeddings.
- Removed the fts_index.json file as it is no longer needed.
- Enhanced the RAG notebook to include updated content and examples using the new index types.
- Adjusted tags in frontmatter to align with the new terminology.

* DA-1319 rename: folders

* DA-1319 update: remove execution outputs and reset execution counts

- Cleared all output cells to ensure a clean notebook state.
- Set execution counts to null for all code cells to allow for fresh execution.
- Adjusted the indexing pipeline to process a larger number of documents (from 100 to 1200).
- Updated the sample query to reflect current news context.

* DA-1319 update: address gemini comments

* DA1319 update: address Shyam's comments

- Clarified the role of the embedding model in generating document embeddings for Vector Search.
- Updated the description of the Couchbase document store integration to specify the use of `CouchbaseQueryDocumentStore`.
- Revised the indexing pipeline steps for better clarity on document processing and storage in Couchbase.

Author: VirajAgarwal1

haystack/fts/RAG_with_Couchbase_Capella_and_OpenAI.ipynb

@@ -0,0 +1,26 @@
+---
+# frontmatter
+path: "/tutorial-openai-haystack-rag-with-hyperscale-or-composite-vector-index"
+alt_paths:
+  - "/tutorial-openai-haystack-rag-with-hyperscale-vector-index"
+  - "/tutorial-openai-haystack-rag-with-composite-vector-index"
+title: "RAG with OpenAI, Haystack, and Couchbase Hyperscale & Composite Vector Indexes"
+short_title: "RAG with OpenAI, Haystack, and Hyperscale & Composite Indexes"
+description:
+  - Learn how to build a semantic search engine using Couchbase Hyperscale and Composite Vector Indexes.
+  - This tutorial demonstrates how Haystack integrates Couchbase Hyperscale and Composite Vector Indexes with embeddings generated by OpenAI services.
+  - Perform Retrieval-Augmented Generation (RAG) using Haystack with Couchbase and OpenAI services while comparing the two index types.
+content_type: tutorial
+filter: sdk
+technology:
+  - vector search
+tags:
+  - OpenAI
+  - Artificial Intelligence
+  - Haystack
+  - Hyperscale Vector Index
+  - Composite Vector Index
+sdk_language:
+  - python
+length: 60 Mins
+---

haystack/fts/frontmatter.md

@@ -0,0 +1,22 @@
+---
+# frontmatter
+path: "/tutorial-openai-haystack-rag-with-search-vector-index"
+title: "RAG with OpenAI, Haystack, and Couchbase Search Vector Index"
+short_title: "RAG with OpenAI, Haystack, and Search Vector Index"
+description:
+  - Learn how to build a semantic search engine using the Couchbase Search Vector Index.
+  - This tutorial demonstrates how Haystack integrates Couchbase Search Vector Index with embeddings generated by OpenAI services.
+  - Perform Retrieval-Augmented Generation (RAG) using Haystack with Couchbase and OpenAI services.
+content_type: tutorial
+filter: sdk
+technology:
+  - vector search
+tags:
+  - OpenAI
+  - Artificial Intelligence
+  - Haystack
+  - Search Vector Index
+sdk_language:
+  - python
+length: 60 Mins
+---