DA-671: Deepseek RAG tutorial (#32)

* added basic code

* changed to openai embeddings

* code is running. text yet to be written

* made the api keys a choice

* updated with automatic batching

* Add conclusion section and update bucket creation note in Deepseek RAG notebook

* updated notebook based on feedback

* updated notebook based on feedback

* Add OPENAI_API_KEY to .env.sample for configuration

Author: teetangh

openrouter-deepseek/.env.sample

@@ -0,0 +1,13 @@
+DEEPSEEK_API_KEY=""
+OPENAI_API_KEY=""
+
+# Couchbase Settings
+CB_HOST=couchbase://localhost
+CB_USERNAME=Administrator
+CB_PASSWORD=password
+CB_BUCKET_NAME=vector-search-testing
+
+INDEX_NAME=vector_search_deepseek
+SCOPE_NAME=shared
+COLLECTION_NAME=deepseek
+CACHE_COLLECTION=cache