docs: Add project page for pgai (#8576)

* docs: Add project page for pgai

* Add pgai to sidebar.js

docs/my-website/docs/projects/pgai.md

@@ -0,0 +1,9 @@
+# pgai
+
+[pgai](https://github.com/timescale/pgai) is a suite of tools to develop RAG, semantic search, and other AI applications more easily with PostgreSQL.
+
+If you don't know what pgai is yet check out the [README](https://github.com/timescale/pgai)!
+
+If you're already familiar with pgai, you can find litellm specific docs here:
+- Litellm for [model calling](https://github.com/timescale/pgai/blob/main/docs/model_calling/litellm.md) in pgai
+- Use the [litellm provider](https://github.com/timescale/pgai/blob/main/docs/vectorizer/api-reference.md#aiembedding_litellm) to automatically create embeddings for your data via the pgai vectorizer.

docs/my-website/sidebars.js

@@ -477,6 +477,7 @@ const sidebars = {
             "projects/YiVal",
             "projects/LiteLLM Proxy",
             "projects/llm_cord",
+            "projects/pgai",
           ],
         },
         "contributing",