docs(supabase): update connection pooler configuration

Modify Supavisor session mode settings in documentation
- Adjust pool mode from transaction to session
- Update default pool size from 20 to 50

Author: jumski

pkgs/pgflow.dev/src/content/docs/edge-worker/prepare-environment.mdx

@@ -58,8 +58,7 @@ If not, see Supabase's [installation guide](https://supabase.com/docs/guides/cli
 1. ### Setup Connection Pool
 
     Modify the `db.pooler` section in your `supabase/config.toml` file
-    to switch to Supavisor **Session Mode**. It's also good to increase the 
-		default pool size:
+    to switch to Supavisor **Session Mode**:
 
     ```diff lang="toml"
       [db.pooler]
@@ -71,8 +70,7 @@ If not, see Supabase's [installation guide](https://supabase.com/docs/guides/cli
     - pool_mode = "transaction"
     + pool_mode = "session"
       # How many server connections to allow per user/database pair.
-    - default_pool_size = 20
-    + default_pool_size = 50
+      default_pool_size = 20
       # Maximum number of client connections allowed.
       max_client_conn = 100
     ```