Update prisma docs (#679)

Author: nfcampos

docs/docs/modules/indexes/vector_stores/prisma.mdx renamed to docs/docs/modules/indexes/vector_stores/integrations/prisma.mdx

@@ -8,6 +8,12 @@ For augmenting existing models in PostgreSQL database with vector search, Langch
 
 Refer to the [Prisma and Supabase integration guide](https://supabase.com/docs/guides/integrations/prisma) to setup a new database instance with Supabase and Prisma.
 
+### Install Prisma
+
+```bash npm2yarn
+npm install prisma
+```
+
 ### Setup `pgvector` self hosted instance with `docker-compose`
 
 `pgvector` provides a prebuilt Docker image that can be used to quickly setup a self-hosted Postgres instance.