Update README to reflect Clickhouse database backend

- Remove outdated statement about being a fully static site
- Add description of Clickhouse database backend for filtering
- Clarify that filtering operations are performed at the database level

Author: Sumer

README.md

@@ -8,7 +8,7 @@ This is a [Next.js](https://nextjs.org/) project bootstrapped with [`create-next
 
 ## Backend
 
-All data is coming from [Synapse](https://www.synapse.org/). We have a Python script that generates a JSON file that contains all the metadata. There is currently no backend, it's a fully static site i.e. all filtering happens on the frontend.
+All data is coming from [Synapse](https://www.synapse.org/). We have a Python script that generates a JSON file that contains all the metadata. The application uses a Clickhouse database backend where all the metadata is stored and filtering operations are performed at the database level for improved performance and scalability.
 
 ## Data Updates