Mark pinecone as node-only (langchain-ai#991)

Author: nfcampos

docs/docs/modules/indexes/vector_stores/integrations/pinecone.md

@@ -1,5 +1,13 @@
+---
+sidebar_class_name: node-only
+---
+
 # Pinecone
 
+:::tip Compatibility
+Only available on Node.js.
+:::
+
 Langchain.js accepts [@pinecone-database/pinecone](https://docs.pinecone.io/docs/node-client) as the client for Pinecone vectorstore. Install the library with
 
 ```bash npm2yarn