Adds a range of reserved usernames to reduce potential misuse by malicious actors (#32828)

config/settings.yml

@@ -21,14 +21,27 @@ defaults: &defaults
   trends_as_landing_page: true
   trendable_by_default: false
   reserved_usernames:
+    - abuse
+    - account
+    - accounts
     - admin
-    - support
+    - administration
-    - help
-    - root
-    - webmaster
     - administrator
+    - admins
+    - help
+    - helpdesk
+    - instance
     - mod
     - moderator
+    - moderators
+    - mods
+    - owner
+    - root
+    - security
+    - server
+    - staff
+    - support
+    - webmaster
   disallowed_hashtags: # space separated string or list of hashtags without the hash
   bootstrap_timeline_accounts: ''
   activity_api_enabled: true