Add "reset" to title of uninstall page and expand content (#503)

website/docs/uninstall.md

@@ -1,5 +1,5 @@
 ---
-title: "Uninstall"
+title: "Uninstall/Reset"
 sidebar_position: 1000
 ---
 
@@ -9,3 +9,27 @@ statement:
 ```sql
 DROP SCHEMA graphile_worker CASCADE;
 ```
+
+(If you are using an alternative schema for Graphile Worker, please update the
+command accordingly.)
+
+:::danger This may also drop some of your database functions/constraints!
+
+Any functionality in your database that depends on Graphile Worker (according to
+PostgreSQL's tracking of dependencies - see
+[pg_depend](https://www.postgresql.org/docs/current/catalog-pg-depend.html) in
+the PostgreSQL docs) may also be dropped by the `CASCADE`; this includes
+database functions (including trigger functions), and foreign key constraints.
+
+It's recommended to try this on a non-production environment first to see its
+effects, and to do a schema-only dump of your database before and after to
+compare the changes and look for unexpected consequences.
+
+:::
+
+:::warning Scale to zero first!
+
+Before running this command, you should make sure there are no running Graphile
+Worker instances.
+
+:::