chore: 🤖 add env vars for clickhouse

server/.env.example

@@ -62,4 +62,10 @@ SVIX_API_KEY=
 
 # ANTHROPIC
 # This is used to generate singular / plural names for your features, which are used when in the dashboard and when you use Autumn UI components
-ANTHROPIC_API_KEY=
+ANTHROPIC_API_KEY=
+
+# CLICKHOUSE
+# This is used to store your events in a ClickHouse database, which is used for usage analytics
+CLICKHOUSE_URL=
+CLICKHOUSE_USERNAME=
+CLICKHOUSE_PASSWORD=