Update rag-on-ai-search.md

Update rag-on-postgresql.md

Update openai-chat-app.md

Update rag-on-ai-search.md

Update rag-on-postgresql.md

Update rag-on-ai-search.md

Update openai-chat-app.md

Update openai-chat-app.md

Merge pull request #2 from gdequeiroz/patch-2

Update link to open Codespaces

Update rag-on-postgresql.md

Update rag-on-postgresql.md

Update rag-on-postgresql.md

Update rag-on-postgresql.md

Update rag-on-postgresql.md