Remove the user accounts information

These are not a thing this year (and aren't likely to be again).

Author: PeterJCLaw

_data/sidebar_tree.yaml

@@ -87,5 +87,3 @@ tree:
     tree:
     - url: /team_admin/discord
       title: Discord Server
-    - url: /team_admin/user_accounts
-      title: User Accounts

team_admin/discord.md

@@ -5,7 +5,7 @@ title: Discord Server
 
 # Discord Server
 
-To assist with communications, especially in a virtual competition, there's a [Discord](https://discord.com/) server for communicating with blue-shirts, your team members and other teams.
+To assist with communications there's a [Discord](https://discord.com/) server for communicating with blue-shirts, your team members and other teams.
 
 If you do not wish to, or are unable to join Discord, you can still get support from <{{ site.emails.teams }}> as normal.
 

team_admin/index.md

@@ -6,4 +6,5 @@ title: Team Admin
 Team Admin
 ==========
 
-The pages in this section cover all of the non-competition related topics, such as [user management](/docs/team_admin/user_accounts).
+See [Discord](/docs/team_admin/discord) for details on the Discord based forums
+where your team can get help & support.