readme: add pgai to readme for semantic search (#8028)

* docs: switch around database integrations order and link to quickstart

* docs: link to blog post in example readme

* chore: link to main readme

* readme: removing example to link externally

readme: removing example to link externally so we don't have to keep this example up-to-date

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README.md

@@ -407,6 +407,7 @@ See the [API documentation](./docs/api.md) for all endpoints.
 
 ### Database
 
+- [PostgreSQL extension pgai](https://github.com/timescale/pgai) (Create and search embeddings from Ollama models using pgvector)
 - [MindsDB](https://github.com/mindsdb/mindsdb/blob/staging/mindsdb/integrations/handlers/ollama_handler/README.md) (Connects Ollama models with nearly 200 data platforms and apps)
 - [chromem-go](https://github.com/philippgille/chromem-go/blob/v0.5.0/embed_ollama.go) with [example](https://github.com/philippgille/chromem-go/tree/v0.5.0/examples/rag-wikipedia-ollama)
 - [Kangaroo](https://github.com/dbkangaroo/kangaroo) (AI-powered SQL client and admin tool for popular databases)